Climate change study at Cambridge Bay, Resolute and Eureka, NU, Canada (1940 to 2022)

[Gray-Wolf]

Are we not seeing another confirmation of the recent paper looking at the impacts of 'dimming' on arctic temps from the 40's to the late 70's here?

Had warming been uninterrupted from the 40's the Arctic would already be ice free and the northern warming would be even more pronounced. Heck! we could be now looking at low winter ice cover and discussing its eventual loss!

[Roger J Smith]

So, the YRB (Resolute) analysis is complete now, and has been edited into previous posts.

I have also upgraded the excel file and compared all of the elements of this study for the two locations. Using 5-yr running means to make the scatter a little less intrusive, but still fairly short-term changes coming into play, these graphs (scroll over to about CA50 if you go into the new file) show pretty clearly what changes are underway and how the changes compare from western to central arctic. It's a little more complicated than just a region wide warming trend but certainly the temperatures are steadily on the increase (except that peaks may have been passed around 2007-12, time will tell on that). 

 

YCBandYRB.xlsx

[Roger J Smith]

I had a look at data for Mould Bay which is about 800 kms northwest of Cambridge Bay on Prince Patrick Island, the furthest west (or northwest) of the sizeable arctic islands. 

This data was available from 1997 to recently. The general impression was that all the same trends as seen at Resolute were acting here as well. The summers before 2006 were much colder than 2007 to 2012, and daily maxima reached the 17-18 C range in this warm spell. In a more "normal" Mould Bay summer, the highest readings are about 10 to 13 C. Mean July temperatures were four degrees higher for several of these years. The anomalous warmth faded away in 2013 which was closer to the average before 2006. The winters at first glance varied in about the same way also. 

This location builds up a 50-80 cm snow pack by May and sees that rapidly melt away in the continuous daylight of May and June. Summer precipitation appears to be sparse compared to either Resolute or Cambridge Bay. What there is of this falls more as rain than snow, but both are recorded in July and August. 

The timing of some of the peak warmth suggests that it built up from east to west across the arctic islands. The warmest days come a few days later at Mould Bay than at Resolute. 

[cheeky_monkey]

On 4/4/2017 at 11:40, Roger J Smith said:

 

Also quite anecdotal, but there has not been a January quite as anomalously warm as 1954 in the western prairies, nor has there been winters as anomalously cold as 1950 or 1969 anywhere in western Canada. Just as there has not been any complete return to the heat wave conditions of 1934 or 1936 in central and eastern regions. The climate is showing some signs of becoming less variable in this AGW period (more dull warmth, sound familiar?). 

 

i couldn't find any warm Januaries in the 1950s let alone an anomalously warm one? 

[Roger J Smith]

Sorry, that was a case of faulty memory, it was actually February of 1954 that set some high temperature records in Alberta, for example, 22.2 (72F as recorded) at High River south of Calgary where it was 17 C. Monthly averages for that month were well above normal too. 

That must have been one of the strongest chinook warmings ever seen around Calgary, the High River daily max temps as recorded in F from 2nd to 8th were 56, 56, 58, 57, 65, 72, and 62. Then there was some snow and a brief cold spell but the second half of the month had frequent highs in the 40s F and low 50s. This warmth spread all the way east to Toronto which also had a record monthly high of 58 F on the 14th (probably since broken). 

[Lettucing Gutted]

Alberta must be the most poleward location to see 20C+ temperatures in the main winter months.  Its at least the most continental location to see those ridiculous summer like temperatures in the 3 main winter months!

Chinooks do seem very variable in their temperatures, at least in winter.  This suggests that the exact source and track of the Pacific air is important.  Those ridiculous winter 20C+ temperatures would require Maritime Tropical on a "Pineapple Express" track far from the southwest.  Maritime Polar westerlies or northwesterlies should only give Chinooks with temperatures slightly above 10C in winter whereas Maritime Arctic northwesterlies would give Chinooks with temperatures slightly below 10C in winter.

Edited April 25, 2017 by Lettucing Gutted

[cheeky_monkey]

On 4/21/2017 at 12:49, Roger J Smith said:

Sorry, that was a case of faulty memory, it was actually February of 1954 that set some high temperature records in Alberta, for example, 22.2 (72F as recorded) at High River south of Calgary where it was 17 C. Monthly averages for that month were well above normal too. 

That must have been one of the strongest chinook warmings ever seen around Calgary, the High River daily max temps as recorded in F from 2nd to 8th were 56, 56, 58, 57, 65, 72, and 62. Then there was some snow and a brief cold spell but the second half of the month had frequent highs in the 40s F and low 50s. This warmth spread all the way east to Toronto which also had a record monthly high of 58 F on the 14th (probably since broken). 

For my location Feb 1954 had a mean ave of -5c...Jan 2001 beats this with a mean of -2.7c

[Roger J Smith]

Updates to previous data posted ...

At Cambridge Bay, snow depth change Apr 30 to May 31 (2017) was 32 cm, from 37 to 5 cm; snow had all melted by June 2nd with the highest temperature seen so far in May and early June, 6.8 C yesterday. 

At Resolute Bay, the spring snow depth max was 34 cm on April 4th. The change during May was -10 cm from 28 at the end of April to 18 at the end of May. That remains the reported snow depth as of June 2nd. Temperatures have remained quite cold, the highest in May was 2.2 and the first two days of June have remained below freezing. 

Next update will include the last frosts, last snowfalls and the summer max and warmest month,  Will post that either mid-August if it looks settled or after August if it remains warm. 

 

 

Edited December 24, 2019 by Roger J Smith

[Roger J Smith]

Some time has passed since I updated this report. 

For Cambridge Bay, the summer and autumn (2017) data are as follows (bear in mind that July 31 is the arbitrary date chosen for end of one frost and snow season and start of the next. Have included the first day in summer with no more than trace snow cover reported.

YEAR ____ Last snow _ snow depth Tr _ last frost __ Warmest mo __ Warmest Day ___ First frost __ first snow __ first -20 C

2017 _____ May 28 _____ June 3 _____ June 12 ___ 9.7 July ______ 22.4 _ July 2 ___ Aug 29 ____ Sept 8 ____ Oct 23

2018 _____ May 30 _____ June 15 ____ July 7 _____8.3 July ______ 18.4 _July 24 ___ Aug 22 ____ Aug 22 ___ Oct 15 (edit later)

... the snow depth change for May 2018 was +4 cm from 24 to 28 cm on the ground at start and end of May.

... it should be noted that summer 2018 was regarded as chilly with persistent ice blocking some of the NWP routes, the mean in August was barely above 5 C (Aug 2017 was almost as warm as July 2017). 

Meanwhile, these are the stats for winter 2017-18 in Cambridge Bay.

2017-18 

coldest month __ -32.5 Feb

coldest min ____ -44.9 Feb 17th

deepest snow __ 31 cm May 9-15

=====================================================

The same data for YRB updated ...

YEAR ____ Last snow _ snow depth Tr _ last frost __ Warmest mo __ Warmest Day ___ First frost __ first snow __ first -20 C

2017 _____ July 15 _____ July 30 _____ July 29 ___ 3.3 July ______ 11.5 _ Aug 12 ___ Aug 8 _____ Aug 8 ____ Oct 24

2018 _____ July 28 _____ July 11* ____ July 31 ___ 1.9 July ______ 14.0 _July 17 ___ Aug 1 ______ Aug 9 ____ Oct 14 (edit later)

... the snow depth change for May 2018 was -12 cm from 31 to 19 cm on the ground at start and end of May.

... * the last snow depth report of 3 cm on July 10, 2018 may have been followed by missing data as it snowed several times with temps close to freezing from mid-July to end of July. 

... there was basically no real summer in 2018 at Resolute Bay, frost and snow continued through the defined seasonal boundary date (Jul 31) and the means in July (1.9) and August (1.3) were among the lowest in the data set. 

 

Meanwhile, these are the stats for winter 2017-18 in Resolute Bay.

2017-18 

coldest month __ -31.9 Feb

coldest min ____ -43.7 Mar 14th

deepest snow __ 32 cm Apr 28 (was near 30 cm constantly from mid-Nov 2017 to early May 2018).

Edited December 23, 2019 by Roger J Smith

[Roger J Smith]

In fact, for Resolute (YRB) the mean of 1.9 in July (warmest month of summer 2018) is coldest in the series, previously it had been 2.2 in 1986 and again in 2004 (also in July of those years). 

A look at the current ice cover map shows that ice has moved down the west coast of Banks Island to contact the mainland near Tuktoyaktuk, and is also well entrenched in waters east of Victoria Island. 

The anomalous cold has spread south into the NWT and parts of the prairies, recently it was -2 C with snow at Edmonton and -1 C with sleet at Calgary. I have to wonder if one cause of the chill at least starting in late July would be dense smoke layers advected north into the subarctic from central British Columbia. In a climate that has such marginal radiation budgets in the first place, blocking out the low sun with smoke would certainly leave an imprint on mean temperatures. 

[Roger J Smith]

The first -20 C readings were on Oct 14 at Resolute and Oct 15 at Cambridge Bay. 

I have updated the excel file provided earlier with all recent data. Link below

 

 

YCBandYRB.xlsx

[cheeky_monkey]

On 24/04/2017 at 10:38, Lettucing Gutted said:

Alberta must be the most poleward location to see 20C+ temperatures in the main winter months.  Its at least the most continental location to see those ridiculous summer like temperatures in the 3 main winter months!

Chinooks do seem very variable in their temperatures, at least in winter.  This suggests that the exact source and track of the Pacific air is important.  Those ridiculous winter 20C+ temperatures would require Maritime Tropical on a "Pineapple Express" track far from the southwest.  Maritime Polar westerlies or northwesterlies should only give Chinooks with temperatures slightly above 10C in winter whereas Maritime Arctic northwesterlies would give Chinooks with temperatures slightly below 10C in winter.

I think it was Jan 2014 had a chinook that sent the temp above 17c in Calgary i was out and about in a t-shirt that weekend.

[Roger J Smith]

Here are updates for the winter of 2018-19 and the summer into autumn 2019 portions of the study. I have also edited in the missing "first -20 C" of autumn 2018 for Cambridge Bay which had not occurred before the previous update (as noted in a later post).

(Feb 14, 2021, have added more data for 2019-20 winter and 2020 summer to first -20 of winter 2020-21. Some provisional numbers follow for winter 2020-21 that may be updated later).

Winter 2018-19 _______ cold mo __ min temp __ max snow __ snow change May _ last frost _ last snow

Cambridge Bay ______ -33.1 Jan _ -41.6 Jan _ 51 cm May 9-14 _ -2cm __ June 13** _ June 11

Resolute ____________-31.7 Jan _ -42.0 Jan _ 29 cm Dec 24 __ -15 cm __July 23 ___ June 23^^

 

Summer 2019 into autumn 2019 __ warm mo _ max temp _ first frost _ first snow _ first -20C

Cambridge Bay _______________ 8.4* Jul _ 21.9 Aug 2 _ Aug 31 _ Oct 7^ _ Oct 26

Resolute ______________________ 5.5 Jul __ 16.1 Jul 26 _ Aug 19 _ Sep 11 _ Oct 27

 

 

Winter 2019-20 ______ cold mo __ min temp __ max snow __ snow change May _ last frost _ last snow

Cambridge Bay ______ -33.4^Feb _ -43.5 Mar _ 25 cm^Apr 2-15 _ 0cm __ June 16 _  note (a)

Resolute _____________ -32.8 Mar _ -44.5 Mar __ 29 cm sev'l Mar-May _ -2 cm _ July 10 ___ June 8

(a) precip appears unreliable for June 2020, no measurable rain or snow, snow on ground until June 15.

also, Resolute Bay snow data indicate several peak accumulations of 29 cm from late March to mid-May, but variable.

looking into this issue to get a more reliable last snow date. 

 

Summer 2020 into autumn 2020 __ warm mo _ max temp _ first frost _ first snow _ first -20C

Cambridge Bay ____________________ 10.8 Jul _ 23.2 Jul 2 _ Aug 29 _ Sep 13 _ Oct 29

Resolute ____________________________ 7.1 Jul _ 19.9 Jul 25 _ Aug 1 _ Aug 3 __ Oct 22

________________________________________________________________________

Winter 2020-2021 (to Mar 8) will be updated when possible

 

Winter 2020-21 ______ cold mo __ min temp __ max snow __ snow change May _ last frost _ last snow

Cambridge Bay ______-33.8 ! Feb _-43.9 Feb _ 36 cm Jan 23 ____ tbd ______  tbd _____  tbd

Resolute _____________  tbd ______ -39.8 Feb _ 26 cm Nov 24-28 _ tbd ______  tbd _____  tbd

 

Notes:

* The mean for July at YCB with no missing days was 8.4, for August with four missing days 8.2, and given the timing, August might have been marginally higher than July.

**The winter at YCB produced a very heavy snow pack by April and May, which was almost all still there by end of May (48 cms). This all melted in the next two weeks and the station has mssing data for three days June 15-17 which is possibly when the last frost actually happened (readings were low but above zero on 18th). 

^ There are numerous missing days for precip data in mid-September and early October, sub-freezing temperatures but no reliable indication of measurable snow (a few traces) in the period September 1 to October 7. Snow depth reported 1 cm on 8th so assumed the first snow no later than Oct 7th. This is an unusually late date and given that temperatures were below freezing most of September, there was likely a measurable snow at some point there. Looking into any sources to clear this up and get a more accurate date. The first -20C seems reliable as there was continuous data from October 8th on. 

^^ At Resolute, the last reported measurable snow was June 23, but traces on July 22-23 left a 1 cm snow depth on July 23 and 24 (which suggests they added up to a measurable amount). The data table will show June 23 however. (a reminder that the snow and frost seasons arbitrarily terminate July 31 and reset from August 1 for the next winter season).

^ (2020) _ Feb 2020 at YCB -33.3, adjusted to -33.4 as 10th missing data during colder spell (est -35). Also the max snow depth of 25 cm in first half of April remained steady at 24 cm through May into early June. 

! _ Feb 2021 _ data available give -33.6 for Feb but 25th missing during colder spell, have estimated -33.8 as monthly mean.

 

Resolute had its 12th snow depth maximum before Feb 1st (2012 was Feb 3) in the data set of 72 winters. The peak of 29 cm was reported on Dec 24, 2018. A secondary max of 25 cm occurred on April 29th. In between it was as low as 22 cm for most of February and March. The snow depth was 24 cm at start of May and 9 cm at end, then dwindled to 3 cm by July 1st after which the ground was bare for most of July, August and the first three quarters of September. Snow depth reports resumed on September 23rd.

There have been enough winters with this early peak to suggest that the "normal" climate has a slightly bimodal distribution, unlike Cambridge Bay which more typically continues to accumulate towards an April or May peak snow depth. At Resolute, some mid-winter thawing can occur when mild maritime arctic air masses move in from an easterly direction. If this tendency is enhanced, then a bimodal winter is more likely. But the average peak from all peak dates is still well on into the spring, just five days earlier than the spring bimodal peak uncontaminated by any late autumn or January peaks. (February peaks are unusual and March not a lot more common).

This was not as cold a summer as 2018 for Resolute and came out closer to long-term averages there. It was a bit on the chilly side of average at Cambridge Bay. 

Attached is the updated excel file with graphs to illustrate some of the trends. 

 

 

 

YCBandYRB.xlsx

Edited March 9, 2021 by Roger J Smith

[Roger J Smith]

Here's another measurement of subarctic winter cold, the lowest temperature in each winter at Dawson, Yukon from the winter of 1898-99 to the present. Once again, will be maintaining this one going forward.

In the table, years identify the winters by their Jan-Mar calendar months. They include the Nov-Dec of the previous year, The station is located near the Yukon-Alaska border about 64 deg N lat. (edit -- see more detailed information on station location and move of recording site Feb 1979 at bottom of the post)

Coldest value of each decade in bold type.

Decade __ 00 ___ 01 ___02 ___03 ___ 04 ___05 ___06 ___ 07 ___08 __09 ____ avg

1899 ____ ---- __ ---- __ ---- __ ---- __ ---- __ ---- __ ---- __ ---- __ ---- __ -42.8

1900-09 _-48.9_-55.6_-45.6_-51.7_-50.0_-46.1_-55.0_-50.6_-42.2_-53.9 __ -50.0

1910-19 _-47.8_-52.2_-52.2_-52.2_-46.7_-38.3_-50.0_-50.6_-52.8_-45.0 __ -48.8

1920-29 _-50.0_-47.2_-47.2_-44.4_-47.8_-52.2_-39.4_-43.3_-46.7_-46.1 __ -46.4

1930-39 _-49.4_-43.3_-52.2_-52.8_-54.4_-48.9_-51.2_-47.8_-47.8_-48.3 __ -49.6

1940-49 _-45.6_-44.4_-46.7_-48.9_-42.2_-41.7_-40.0_-58.3_-43.3_-50.0 __ -46.1

1950-59 _-51.2_-51.2_-54.4_-48.3_-47.8_-49.4_-50.0_-50.6_-43.3_-53.3 __ -49.9

1960-69 _-45.6_-43.9_-54.4_-52.8_-48.3_-54.4_-50.6_-51.7_-54.4_-51.2 __ -50.7

1970-79 _-48.9_-56.2_-52.8_-52.2_-48.9_-52.8_-52.2_-40.0_-48.9*_-55.8__ -50.9

1980-89 _-53.8_-51.8_-50.2_-51.4_-49.9_-49.6_-43.5_-46.3_-43.5_-51.2 __ -49.1

1990-99 _-52.2_-47.8_-42.4_-50.2_-50.3_-45.1_-50.0_-52.0_-47.5_-48.0 __ -48,5

2000-09 _-47.5_-42.5_-42.0_-42.0_-48.5_-50.5_-45.5_-48.7_-51.3_-50.3 __ -46.9

2010-19 _-46.0_-47.4_-46.2_-50.3_-46.7_-47.1_-35.9_-42.6_-44.9_-44.3 __ -45.1

2020 ___ -47.7 _ -46.2_-49.8_-47.2

(complete through winter 2022-2023)

* Jan 1978 old and new stations both reporting data, the new location (CYDA) supplies the data from Feb 1979 and thereafter. The minimum at CYDA for the same month was -51.0. See note at bottom of the post.

About half of winters have this minimum in January with a strong peak of dates in the mid-month interval. The list below shows which winters had a minimum in another month: It is possible for temperatures to fall as low as -40 C from about 7th November to early April although such readings are rare outside the span of late November to early March. With ties counting 0.5, in 102 winters to date, the minimum has occurred 2.5 times in NOV, JAN 53 (56 cases, six tied with DEC or FEB), DEC 22 (24 cases, 4 ties with JAN), FEB 24.5 (26 cases, 2 tied with JAN, 1 with NOV) and MAR counts zero but has had six near misses. APR 1944 had a reading cold enough to be a winter minimum in the least extreme cases.

NOV _ 30th (1930, mild through the winter, second cold spell mid-March 1931 reached -41.6).

__ 15th-16th (1945-46) tied with 10th Feb 1946 _ 21st (1986-87) 

DEC _ 31st (1901-02)* _ 25th (1917-18) _ 15th (1918-19) _ Dec 6 (1925)^^ _ Dec 28 (1927-28)

____ 31st (1929-30)* _ 21st-22nd (1936-37) _ 8th (1941-42) _ 29,30,31 (1944-45) _ 

____ 7th-8th (1948-49) _ 31st (1949)* _ 29th-30th (1954-55) _ 12th (1956-57) also -50.0 Feb 12 1957.

____ 30th (1961-62) .. Jan 27th, 1962 almost as cold (-53.9) _ 11th (1966-67) _ 10th (1975-76)

____ 5th-6th (1976-77) _ generally a milder than average winter _ 5th, 9th (1977-78) _ 28th (1980-81)

____ 4th-5th (1990-91) _ 4th (1991-92) _ 1st (1994-95) __ 31st (1999-2000)* _ 17th (2000-01)

____ 25th (2015-16) _ a very mild January followed, Feb somewhat colder

FEB _ 4th (1908), 2nd (1910)** _ 17th (1915)^ _ 1st (1917) by 0.6 _ 6th (1921) _ 10th (1922)

____ 23rd (1932) _ 8th-9th (1939) _ 7th (1943) _ 10th (1946) tied with Nov 15, 16 1945.

____ 3rd (1947) in this extreme spell, -63 C at nearby Snag was the all-time North American low. ..

______ Jan 1947 averaged -31.6 and had fallen to -52.8. There was also a reading of -51.7 on 13-14 Dec 1946.

____ 16th (1948) _ 17th (1954) -- tied with 28th Jan, corrupted data for most of Jan, not certain a lower value 

______ did not exist. __ 9th (1958) _ 21st, 22nd (1961) _ 5th (1963) _ 3rd (1968) _ 11th (1979)

______ 12th (1985) _ 18th (1986) _ 4th (1993) _18th (2003) _ 23rd (2007) _ 12th (2014) __ 6th, 7th (2015)

______ 7th (2018) _ 

MAR _Mar 1908 (-41.1) came within 1.1 of the February minimum.

_____ Mar 2 1956 was -47.8, within 2.2 of the January 1956 min.

_____ Mar 7th 1961 (-43.3) was within 0.6 of the February 1961 min.

_____ Mar 5th 1987 (-45.2) was colder than any days Dec 1986 to Feb 1987 but not Nov 1986.

_____ Mar 13th 2003 (-41.5) was within 0.5 of coldest day Feb 18th 2003.

_____ Mar 2nd 2007 (-47.5) was within 1.2 of coldest day Feb 23rd 2007.

APR _ (In 1944 the Jan min of -42.2 was almost broken on April 3 -40.6).

* tied coldest Dec 31 1901 and Jan 1 1902 and also Dec 31 1929 and Jan 1 1930 (Feb 15 within 0.5).  A third similar event was Dec 31 1949 and Jan 1 1950 (followed by record cold throughout western Canada). Then Dec 31, 1999, tied with three days in January 2000 for coldest of that winter.

** tied coldest Feb 2 1910 with Jan 10, 11, 1910.

^ a much milder Jan 1915 than most, -31.3 the lowest temp, both Dec 1914 and Feb 1915 colder.

^^ another very mild Jan 1926 with another colder spell late Feb 28 (-38.9) within 0.5 of the Dec 6 minimum.

___________________________________________________________________________________

LOCATION INFO: The town of Dawson (pop 1500) is located at the confluence of the Yukon and Klondike rivers. The first recording site (1898-1902) has a lat-long which places it 10 km east of Dawson and 1 km north of the Klondike highway running east-west at that point. I suspect this was an approximation since there is no sign of human activity there (it is north of the river, all human activity is to the south). The elevation is given as 320m asl. By 1902, the station was either relocated or better identified at a position which is 1 to 2 km east of Dawson near the current baseball diamond and recreation hut (same elevation). The area is flat with a glacial moraine type hill to its north. In 1978 a weather station was opened at the airport (CYDA) located about 20 km east of this first site, beside the same (and only access) highway at 370m asl. After Jan 1979 the longer-reporting location ceased reporting but we have overlap for one full winter and parts of a second one. This overlap shows that the airport location is 1 to 2 deg colder on average in colder months, including on coldest nights. For the winter of 1977-78 the average temperature difference was zero, but one mild month (Feb 78) was 2 deg milder while the other two were each one degree colder at the airport. The three monthly extremes were all colder at the airport by 0.9, 2.1 and 0.3 deg. There was a difference of one degree in Jan 1979 (but the extreme comes from a very cold Feb 1979 with only the airport reporting at that point). 

I have drawn the conclusion that the colder half of the data 1979 to 2019 may be 1 to 2 deg colder than a comparative sample of that colder half 1899 to 1978, but that the milder half the data may be more equally comparable. 

==============================================================================

ANALYSIS of the data series

Briefly, the analysis shows that there have been three milder intervals, one lasting approximately 1919-31, another from 1940-46, and then generally speaking since about 2001 to present with 2008 and 2009 somewhat colder to produce 2001-07 and 2010-19. (This is the winter of 2020 in the same time scale, and so far it seems on course to get back to somewhat colder values). Within each mild spell there appears to be one to three particular winter(s) that were exceptionally mild and therefore likely dominated by Pacific air masses due to ridge development near 130W, and these were the winters of 1926, 1944-46, 2002-03 and 2016. The winter of 1975-76 was also quite mild but fell within a generally cold interval.

The coldest five-winter average and ten-winter average would identify the interval 1965 to 1975 as the coldest part of the data series although it was just about at the same level in the decade of 1900-09 and in the mid-1930s and 1950s. The early 1980s remained very cold, then warming seemed to begin, however it backed off during the 1990s (albeit the data should be reduced by 1-2 deg for direct comparison to decades before 1980). 

A note to any researchers thinking of using Dawson data: some of the very early cold interval reports have only daily minima during extreme cold spells (because presumably going outside once a day was more than enough for the recorder) and so the averages which are still tabulated anyway are incorrect for these months as only the non-extreme cold days have a maximum reported. This practice seemed to fade out of the data after 1910. Also, the winter of 1953-54 have some evidently incorrect data, for one thing, only minima are reported, but a good number of the January minima seem to be entirely erroneous (numbers well above 0 interspersed with more authentic looking numbers) while Feb 1954 has what appears to be correct minima. I would suggest some additional quality control might be needed for January 1954 data from the station. 

Edited December 10, 2023 by Roger J Smith
added 2022-23

[Roger J Smith]

Here are some similar data (compaed to Cambridge Bay and Resolute) for Eureka, which is further north located in central Ellesmere Island, at 80N 86W and just 10 meters above sea level in a glacial valley surrounded by permanent ice fields and glaciers. Since the summer here is quite brief, I have left out the variables such as last frost, last snow cover, first frost and first snow cover. We'll check the trends on temperatures of both extremes, maximum snow depth and first autumn -20 C reading.. It should be noted that the prevailing climate is much drier than in the central arctic islands, and 10-15 cm snow cover is quite typical with strong winds sometimes leading to patches of bare frozen ground.

The climate is drier than further south, and is known as "arctic desert" although it does support some scrubby vegetation that persist despite a very short growth season mid-June to early August. Most summers have very little rain and can continue to see sporadic light snowfalls, but one or two cases were noted of 25 mm rainfalls. A daily snowfall of more than 10 cm would be unusual at any point in the season. One heavier snowfall noted was 18 cm Sept 17-19 1966. The snow pack stays fairly constant once it reaches maximum depth and only begins to melt at the very end of May or first week of June. |At this latitude, darkness begins in early November and lasts until mid-February. Continual daylight begins in late April and persists to early August.

The min temp and coldest month could be in the preceding Nov or Dec although usually as shown they are in the part of the winter in the same calendar year. So what is showing is the coldest reading of each winter, not each calendar year.

 

YEAR ____ Min temp _ coldest mo __ Max snow depth ___ Max temp _ warmest mo __ first -20

1948 _____ -52.8 Mar __ -42.6 Feb __ _____________ ___ 18.9 Jul ___ 6.2 Jul _____ Sep 17

1949 _____ -49.4 Dec __ -41.8 Dec __ _____________ ___ 15.0 Jul ___ 5.9 Jul _____ Sep 29

1950 _____ -50.6 Feb __ -42.0 Jan __ _____________ ___ 19.4 Jul ___ 6.1 Jul _____ Sep 17

1951 _____ -50.0 Jan __ -40.3 Feb __ _____________ ___ 15.6 Jul ___ 5.7 Jul _____ Sep 27

1952 _____ -51.2 Jan __ -38.8 Dec __ _____________ ___ 16.7 Jul ___ 6.7 Jul _____ Oct 1

1953 _____ -50.6 Mar __ -39.6 Feb __ _____________ ___ 12.8 Jul ___ 4.2 Jul _____ Sep 23

1954 _____ -47.8 Feb __ -38.4 Jan __ _____________ ___ 16.1 Jun ___ 5.6 Jul _____ Oct 2

1955 _____ -48.9 Feb __ -40.1 Mar __ _____________ ___ 13.3 Aug ___3.8 Jul,Aug _ Oct 2

1956 _____ -52.2 Mar __ -37.7 Mar __37 cm Apr 17-Jun 2 _ 14.4 Jul ___ 5.5 Jul _____ Sep 23

1957 _____ -48.9 Jan __ -40.5 Jan __ 10 cm Mar 1-May 14_ 17.8 Jun __ 6.8 Jul _____ Sep 29

1958 _____ -52.2 Feb __ -41.5 Dec __23 cm Jan 23-May 17_18.9 Jul __ 5.8 Jul _____ Oct 2

1959 _____ -48.3 Feb __ -39.6 Mar __20 cm Jan 20-May 31_16.7 Jul __ 6.3 Jul _____ Sep 29

1960 _____ -51.2 Mar __ -39.5 Mar __23 cm May 6-14 _____17.2 Jun __ 6.6 Jul _____ Oct 1

mean _____ -50.3 _____ -40.2 _____ 23 cm Mar 7-May 10 __16.4 _____ 5.8 ________ Sep 27

 

1961 _____ -51.2 Mar __ -39.7 Mar __18 cm Feb 18-May 30 _15.6 Aug _ 4.5 Jul _____ Sep 14

1962 _____ -46.7 J, F __ -39.1 Feb __ 28 cm Apr 1-29 _____ 18.3 Jul __ 7.5 Jul _____ Sep 26

1963 _____ -48.9 Jan __ -39.1 Mar __ 28 cm Feb 11-May 27_ 15.0 Jul __ 5.8 Jul _____ Sep 29

1964 _____ -51.2 Mar __ -38.8 Mar __ 25 cm Apr 30-May 7 __12.2 Aug _ 3.7 Aug _____Sep 28

1965 _____ -45.2 Feb __ -37.2 Feb __ 15 cm May 7 - 21 ____ 16.7 Aug _ 4.1 Jul _____ Sep 20

1966 _____ -53.3 Jan __ -39.4 Mar __ 18 cm May 11-21 ____ 14.4 Aug _ 5.3 Aug _____Sep 25

1967 _____ -51.7 Feb __ -41.7 Feb __ 23 cm Jan 4-Apr 4 ___ 14.4 Jun _ 4.5 Jul _____ Sep 25

1968 _____ -51.2 Jan __ -40.0 Jan __ 20 cm Feb 24-Apr 30 _ 18.3 Jul __6.3 Jul _____ Sep 29

1969 _____ -48.3 Mar __ -38.6 Mar __ 18 cm May 9 - 21 ____ 13.3 Jun _ 4.6 Jul _____ Sep 19

1970 _____ -50.6 Jan __ -37.9 Feb __ 30 cm Apr 10-May 22 _ 13.3 Aug _ 5.3 Jul _____ Sep 24

mean _____-49.9 ______-39.2 ______22 cm Mar 26- May 12 _ 15.2 ____ 5.2 ________Sep 24

======================================================

In these first 23 years of data, not much change decade to decade, there was a slight decrease in the summer temperature parameters and the -20 C season began a bit earlier (by three days). Will be posting the continuation of these tables over the next 2-3 days. 

Edited January 14, 2020 by Roger J Smith

[Roger J Smith]

Continuing with the data for Eureka ...

YEAR ____ Coldest min and month ___ Max snow depth ______ Warmest max and month __ First -20 C

1971 _____ -48.9 D, F __ -42.5 Feb __ 30 cm May 7-20 ________ 17.2 Jul __ 7.0 Jul _____ Sep 24

1972 _____ -53.9 Feb __ -39.4 Jan ___23 cm Mar 10 - June 3 ___ 11.7 Jul __ 4.6 Jul _____ Sep 20

1973 _____ -52.8 Feb __ -43.2 Feb __ 28 cm Apr 4 - May 1 _____ 11.1 Jul __ 4.5 Jul _____ Sep 26

1974 _____ -50.6 Feb __ -42.3 Jan __ 18 cm Apr 16 - June 22 ___ 12.8 Jul __ 4.8 Jul _____ Sep 22

1975 _____ -51.7 Feb __ -42.9 Feb __ 25 cm Nov 14-27 1974 ____16.1 Jul __ 4.9 Jul _____ Sep 26

1976 _____ -47.8 Mar __ -37.5 Feb __ 28 cm Apr 3 - May 31 _____18.9 Jul __ 5.1 Jul _____ Sep 21

1977 _____ -50.5 Mar __ -42.2 Mar __ 23 cm Jan 16 - Feb 6 _____ 17.5 Jul __ 6.7 Jul _____ Sep 25

1978 _____ -50.8 Dec __ -39.9 Dec __48 cm May 13 - 22 ________17.3 Jul __ 6.8 Jul _____ Sep 27

1979 _____ -55.3 Feb __ -47.9 Feb __ 20 cm Apr 13 - May 2 _____ 14.5 Jul __ 5.2 Jul _____ Sep 14

1980 _____ -49.8 Jan __ -38.4 Dec __ 34 cm Mar 21 - 27 ________14.7 Jul __ 5.5 Jul _____ Sep 17

mean _____-51.2 _____ -41.6 ______28 cm Mar 18 - Apr 18 _____15.2 Jul__5.5 Jul _____ Sep 22

------------------------------------------------------------------------------------------------------

ANALYSIS: The 1970s began with some very cold years, 1972 to 1974 failed to warm beyond about 12 C and had warmest months (always July in this decade) below 5.0. This reversed to some extent in the later 1970s with some rather warm readings. The winters were generally a bit colder than previous decades, and reached new minima in 1972 and again in 1979 (-55.3) during a widespread very cold month in eastern North America. To the end of this decade there is no sign of any warming trend overall but a few years began to display signs of it. Similar to Cambridge Bay, winter 1974-75 had an anomalous early winter snow depth peak in November 1974. This pulled back the average duration which otherwise would have run from early April to early May on average. The decade had somewhat heavier snow cover than previously. The winter of 1977-78 had particularly heavy snow cover for this location. It had reached its usual late winter depth before the end of 1977 and continued to accumulate with small snowfalls in the heart of the winter season. Some mid-winter periods have no measurable snow and changes can only occur through wind redistribution, which is unusual due to prolonged anticyclonic intervals and rather calm conditions. Stronger winds occur in summer as different surfaces are heated and sometimes gusts over 100 km/hr occur in dry weather in July. 

We are now in a position to set the 1951-80 "normal" based on those years from previous post and this one. Data from 1948 to 1950 are not included in these.

1951-80 _____ -50.4 __ -40.0 ____ 24 cm Mar 19 - May 2 _____ 15.5 ___ 5.5 _____ Sep 25

The trends within this 30-year interval are faint, but slightly towards a colder regime with more snow and earlier winter onset. 

Frequencies of coldest and warmest (0.5 for ties) -- these data include 1948, 49 and 50.

Coldest Days ___ 2.5 Dec, 8.5 Jan, 13.0 Feb, 9.0 Mar ______ Warmest Days __ 4 Jun __ 23 Jul __ 6 Aug

Coldest Months _ 5 Dec _ 6 Jan _ 12 Feb _ 10 Mar _________Warmest Months _______ 30.5 Jul _ 2.5 Aug

Now we can start to track how that changed, if at all, from 1981 to the present time. 

=============================================

1981 _____ -46.3 Feb __ -37.7 Mar __ 13 cm Apr 14-20 _____ 17.2 Jun __ 5.9 Jul _____Sep 27

1982 _____ -47.9 Mar __ -39.0 Feb __ 18 cm Apr 19-27 _____ 14.2 Jul __ 5.1 Jul _____ Sep 24

1983 _____ -50.2 Feb __ -37.8 Feb __ 19 cm Apr 10-12 _____ 13.6 Jul __ 5.7 Jul _____ Oct 4

1984 _____ -51.3 Mar __ -44.1 Feb __ 20 cm Feb 4-12 ______ 15.2 Jul __ 5.3 Jul _____ Sep 28

1985 _____ -49.8 Mar __ -41.5 Feb __ 38 cm Apr 19-24 _____ 14.5 Jul __ 6.6 Jul _____ Oct 1

1986 _____ -50.7 Jan __ -41.8 Mar __ 22 cm Apr 9 - May 1 __ 11.3 Jul __ 4.3 Jul _____ Sep 21

1987 _____ -55.3 Feb __ -45.2 Feb __ 22 cm Jan 29-Feb 2 __ 16.6 Jun __ 6.0 Jul _____ Sep 26

1988 _____ -52.6 Jan __ -39.3 Jan __ 15 cm Feb 20-Mar 10__ 17.5 Jul __ 7.3 Jul _____ Oct 6

1989 _____ -52.4 Jan __ -42.5 Jan __ 22 cm Mar 5 - 9 ______ 11.9 Jul __ 4.2 Jul _____ Sep 28

1990 _____ -51.5 Jan __ -40.8 Feb __ 26 cm May 9-15 ______15.7 Jun__ 5.6 Jul _____ Oct 1

mean _____-50.8 _____ -41.0 ______ 22 cm Mar 27-Apr 5 ___14.8 _____ 5.6 Jul _____ Sep 29

-------------------------------------------------------------

ANALYSIS:

 

In general terms, there was not much change from the previous 30-year averages in the 1980s to 1990 -- but the onset of -20 C temperatures came a few days later with 1988 in particular having some difficulty settling into the winter chill. 

Note: An unusual incursion of milder air on very strong northwest winds (gusting to 100 km/hr) took place on Jan. 24th 1982. Temperatures peaked at -9.6 C. In most winters readings higher than -20 are rare. No precip was noted within weeks of this date, except for trace amounts of snow which could have been just blowing snow. Very strong southerly winds occurred and some light snow fell earlier in the month (9th). This was during an unusually cold outbreak in eastern North America. 

Then in Oct 1984, an unusual mild spell (near freezing) and heavy snow led to a 27 cm cover by Oct 14th (normal is about 5-10 cm). After increasing to 28 cm in mid-November, this pack continued to grow incrementally to 35 cm in late March and 38 cm in late April, with consistently very cold temperatures all through the period. April 1985 was particularly cold relative to normal values (mean -30.9). This perhaps shows us how a slight increase in the snow pack can really anchor colder air masses in these arctic source regions. Despite rather mild temperatures after mid-May, the snow pack melted off rather slowly and only disappeared finally by about June 28th (1985), about two weeks later than most years. It gave me the impression that a 60-80 cm snow pack might manage to last through an entire summer at that location, if the climate ever shifted in such a way as to produce that much snow. (Normally late June and all of July are snow free with 5-15 mm rainfalls, and then snow begins to fall again in August).

-------------------------------------------------------------------

Will continue and hopefully finish this study in the next day or two. 

Edited January 14, 2020 by Roger J Smith

[Roger J Smith]

Moving towards the completion of the Eureka data set ... a reminder that min temp and coldest month can be in the Nov-Dec of the preceding year since this tracks winters rather than calendar years. Also the max snow depth can be before January of the stated year, but so far this has only been noted once (in 1974-75). The other data will always be in the calendar year quoted. 

YEAR ___ Min temp _ coldest mo __ Max snow depth ____ Max temp _ warmest mo_ first -20 C

1991 ____ -50.7 Jan _ -40.1 Jan ___ 20 cm Apr 30-May 4 _ 16.1 Jul __ 6.4** Jul ___ Sept 29

1992 ____ -49.1 Jan _ -40.6 Jan ___ 21 cm Mar 21-Apr 8 __15.1 Jul __ 5.2 Jul _____Oct 3

1993 ____ -48.9 Mar _ -36.6 Mar ___20 cm May 12 - 15 ___16.7 Jul __ 7.3 Jul _____ Sept 28

1994 ____ -49.9 Mar _ -37.6 Mar ___08 cm Apr 22-May 9 _ 17.6 Jul __ 5.6 Jul _____ Oct 2

1995 ____ -52.0 Mar _ -39.2 Mar ___10 cm Mar 14-Apr 8 __18.6 Jul __ 7.3 Jul _____ Oct 3

1996 ____ -48.7 Feb _ -38.2 Mar ___16 cm Nov 27-28 ^ ___12.0 Jul __ 4.1 Jul _____Sept 14

1997 ____ -49.7 Feb _ -41.0 Feb ___19 cm Jan 15-29 ____ 15.6 Jun __ 5.6 Jul ____ Sept 23

1998 ____ -47.6 J F __-39.2 Jan ___ 19 cm May 18 ______ 17.8 Jul __ 6.9 Jul _____Oct 11*

1999 ____ -46.6 J M __-38.8 Jan ___ 21 cm May 14-15 ___ 16.5 Aug__ 7.0 Jul _____Oct 3

2000 ____ -50.2 Jan _ -41.4 Dec ___ 13 cm Apr 14-May 16_ 19.6 Jul __ 6.2 Jul _____Sept 28

mean ____ -49.3 ____ -39.3 _______ 17 cm Mar 28-Apr 9 _ 16.6 _____ 6.2 Jul _____ Sept 29

_________________________________________________________

Notes:

* September 1998 was much above normal in temperatures. There were few days even reaching -5 C and this milder trend continued for the first ten days of October. A more normal temperature regime was not reached before about late November although the entire winter season was relatively mild for the location, except for a near normal January of 1999. This was also a strong El Nino year and the warmest year on record at Toronto. 

** Unfortunately the station reported no data from July 21 to 31 then resumed operation on August 1st. The 6.4 could have ended up between 5 and 8 given the normal range of temperatures in late July. Also the annual max of 16.1 could have been superseded. The first week of August 1991 was relatively mild there, so my guess is that the warmth of mid-July probably continued and the actual monthly mean might have been closer to 7.0. 

^ This early peak snow depth was almost matched by 15 cm reported at times in March, April and May. There was unusually heavy snow in June 1996, 8.2 cm fell on June 9-10 at a time when the winter snow pack (not very large at any point) had mostly melted away. Another 3 cm fell on June 25. It is rare to see near-freezing (all day) temperatures and snowfall that late into June or at any point in July. But after a notably cold July there was more snow on July 23 and 27 (2-3 cm falls in each case). August continued with the colder than normal theme with a mean of only 1.0 (some milder Augusts are in the 3-5 range). There was a fall of 7.6 cm snow on August 20th which is also unusual as many Augusts see only small or trace amounts. This cover only lasted one day. Then the -20 C season began about two weeks earlier than most years. 

ANALYSIS

While the decade of the 1990s to 2000 produced some variations, the background theme was slight warming. A new maximum of 19.6 was reached on July 29th, 2000, but the warmest month in the data set so far remained 7.5 in July 1962 (partially missing July 1991 may have been close to that and two more 7.3 values were added to the one produced in July 1988. Snow depth continued its slow decline, with winters of 1993-94 and 1994-95 particularly sparse (both maxed out at 8-10 cm).  The timing of maximum snow depth changed only slightly from earlier averages and that was largely due to two anomalously early peaks, one in November 1995 and the next one in the following winter in January 1997. The onset of the -20 C season drifted back to near the end of September and on one occasion was two weeks late in arriving (Oct 1998). 

=================================================================

(will post again with remainder of the data)

 

 

[Roger J Smith]

YEAR ___ Min temp _ coldest mo __ Max snow depth ____ Max temp _ warmest mo_ first -20 C

2001 ____ -51.2 Feb __ -37.1 Feb __ 15 cm (two int) ** ___ 15.0 Jul __ 5.5 Jul _____Sept 24 ^

2002 ____ -48.4 Feb __ -40.6 Feb __ 21 cm Apr 30-May 5 _13.8 Jul __ 5.5 Aug ____ Oct 2

2003 ____ -46.1 Feb __ -38.1 Mar __ 20 cm Feb 7-15 ____ 20.0 Jul __ 7.6 Jul _____ Oct 4

2004 ____ -49.5 Mar __ -39.3 Mar __ 14 cm Apr 13-25 ____11.5 Jul __ 4.5 Jul _____ Sept 23

2005 ____ -50.2 Mar __ -36.0 Jan __ 29 cm Apr 16-17 ____ 15.2 Aug__7.2 Jul _____Oct 1

2006 ____ -46.8 Mar __ -35.5 Feb __20 cm^^Nov 30-Dec 1_15.3 Jul __ 6.4 Jul _____ Oct 5

2007 ____ -49.7 Mar __ -39.4 Mar __ 16 cm Apr 16-May 1 _ 20.7 Jul __ 7.9 Jul _____ Oct 3

2008 ____ -49.7 Mar __ -41.0 Jan __ 17 cm Feb 3 ________18.6 Jul __ 7.1 Jul _____ Oct 6

2009 ____ -50.1 Feb __ -38.6 F M __ 19 cm May 19-24 ___ 20.9 Jul __ 8.0 Jul _____ Oct 6

2010 ____ -45.4 Jan __ -34,7 Jan __ 30 cm Apr 23***_____ 18.5 Jun __ 6.7 Jul _____ Oct 2

mean ____ -48.7 _____ -38.0 ______20 cm Mar 20-Apr 1 __17.0 _____ 6.5 (Jul) ____ Oct 2

____________________________

** In 2001, two intervals had 15 cm snow cover, March 5-15 and May 6-16. The stats are averaged into the data means by duration of March 5 to May 16.

^ Rather like 1998, most of September was very mild and this early -20 was followed by more mild weather than is usually the case once -20 has been reached. The days from Sept 27th to October 4th were close to freezing at times and some snow melted. Another restart of the -20 C season occurred on October 10th without a return to mild conditions. 

^^ An unusually heavy snowfall (10.8 cm on Nov 29, 2005) led to a temporary peak in snow depth of 20 cms. This settled to the 10-15 cm range within a week. Another maximum of 19 cms persisted through large parts of March and April but never broke the brief 20 cm earlier in the winter. 

*** April 2010 was very different from most Aprils (which tend to be quite dry with stable snow packs near seasonal maximum). There was a total of 19 cms snow and some very mild temperatures in the -5 to -10 C range mid-month. The snow pack built up to its maximum then gradually settled back to 25 cm. One more snowfall brought it back to 29 cm on May 12th and that settled to 20-25 cm for a few weeks before it gradually melted in June. 

note Feb 2006 may have been closer to -36 as one day of data missing and days on either side were cold. 

------------------

ANALYSIS (2001-2010) ...

This decade continued a very slight temperature increase trend, adding about 1 C to the means of the previous decade in winter and less than 0.5 deg in summer. There was more variability perhaps, and some of the summers were notably warm, in particular 2009. The onset of winter (first -20 C) was further delayed to early October. There were several more episodes of very mild conditions in September and/or October, including the autumn of 2006. Snow pack maximum depths improved slightly over the minimum reached the previous decade, but began to show more of a bimodal tendency in this decade with several occasions of one "autumn" or early winter peak and a second similar spring or late winter peak. There was a noted tendency for snow depths to deflate after unusual mid-season snowfalls, possibly indicating greater water content in the snow than one might expect in this arctic desert climate. 

We can now compare the 1981-2010 averages to the 1951-1980 averages previously calculated. 

1951-80 _____ -50.4 __ -40.0 ____ 24 cm Mar 19 - May 2 _____ 15.5 ___ 5.5 _____ Sep 25

1981-2010 ___ -49.6 __ -39.4 ____ 22 cm Mar 25 - Apr 5 _____ 16.1 ___ 6.1 _____ Sep 30

The frequency of various extremes compares to the first set as follows ...

1948-80 ___ Winter min _______________ 1981-2010 ___ Winter min  __________ Total (63 winters)

__ 2.5 Dec, 8.5 Jan, 13.0 Feb, 9.0 Mar ____ 0.0 Dec, 9.0 Jan, 9.5 Feb, 11.5 Mar ___ 2.5 Dec, 17.5 Jan, 22.5 Feb, 20.5 Mar

1948-80 ___ Coldest month ____________ 1981-2010 ___ Coldest month ________Total (63 winters)

__ 5 Dec _ 6 Jan _ 12 Feb _ 10 Mar ______ 1.0 Dec, 9.0 Jan, 10.5 Feb, 9.5 Mar ___ 6.0 Dec, 15.0 Jan, 22.5 Feb, 19.5 Mar

1948-80 ___ Summer max ______________ 1981-2010 __ Summer max _________ Total (63 summers)

____ 4 Jun ___ 23 Jul ___ 6 Aug _________ 5 Jun __ 23 Jul __ 2 Aug ___________ 9 Jun __ 46 Jul __ 8 Aug

1948-80 ___ Warmest Months ___________ 1981-2010 __ Warmest Months ______ Total (63 summers)

____ 0.0 Jun ___ 30.5 Jul ___ 2.5 Aug _____ 0 Jun ___ 29 Jul ___ 1 Aug _________ 0 Jun __ 59.5 Jul __ 3.5 Aug

There have not been large shifts in these distributions, the coldest part of winter continues to be mid-January to early March, and

the warmest part of summer late June to early August. The years that have their warmest day outside of July usually hit a day within a week of July, mid-June to mid-August is the extreme range (compared to mid-May to late September in southern Canada). 

====================================================

(2011-2020 stats)

YEAR ___ Min temp _ coldest mo __ Max snow depth ___ Max temp _ warmest mo_ first -20 C

2011 ____ -49.5 Feb __ -38.8 Feb __ 34 cm Jan 2 - 3 ____ 20.0 Jul __ 9.8 Jul _____ Sept 28

2012 ____ -50.4 Mar __ -37.2 Mar __ 30 cm Apr 2 -11 ____ 17.9 Jul __ 8.7 Jul _____ Oct 8

2013 ____ -51.5 Mar __ -42.3 Feb __ 20 cm Mar 27-Apr 6__12.8 Jul __4.5 Jul _____ Oct 4

2014 ____ -50.4 Feb __ -39.1 Feb __ 29 cm Mar 23-Apr 3__14.6 Aug__5.9 Jul _____ Oct 3

2015 ____ -49.2 Feb __ -36.9 Mar __ 12 cm Jan 23-25 ____20.2 Jul __ 9.6 Jul _____ Sept 28

2016 ____ -47.8 Dec __ -37.4 Dec __ 15 cm Apr 6-May 17_ 18.1 Jul __ 8.2*Jul _____ Oct 9

2017 ____ -50.7 Mar __ -34.8 Mar __ 22 cm May 24 ______13.8 Jul __ 5.5 Jul _____ Sept 26

2018 ____ -46.3 Mar __ -38.0 Mar __ 14 cm May 9-10 ____ 14.5 Jun __4.5^Jul _____ Oct 1

2019 ____ -46.5 Mar __ -36.5 Feb __ 26 cm Jan 1*** _____ 19.0 Jul __ 9.7^Jul _____ Oct 17

2020 ____ -49.1 Mar9__-39.7 Jan ___ 9 cm Apr 5 _________ 19.5 Jul _ 10.0 Jul _____ Oct 8

mean ____ -49.2 _____ -38.1 _______ 20 cm Mar 17 - 24 ___ 17.1 _____ 7.7 Jul _____ Oct 5

 

2021 ____ -48.0 Feb 21_ -35.0 Feb _ 17 cm (sev'l Jan-Feb) __13.7 Jun _ 5.4 Jul ____ Oct 15

2022 ____ -47.5 Feb 5 __ -38.0 Feb _ 29 cm (late Oct-early Jan)*_19.2 Jul _ 6.7 Jul ___ Oct 2

2023 ____ -49.2 Jan 12 __ -36.8 Feb _ 12 cm (21 Jan) _______ 19.7 Jul _ 8.0^ Jul ___ Oct 9

( to Dec 10 2023)

*snow cover of 27-29 cm fairly continuous late October to Jan 5, then it suddenly changes to 14 cm on Jan 6 and stays in that range rest of winter, slowly reducing to zero by June 7. Not sure if that change reflects a windstorm blowing snow away, or a change in observer with different habits, cannot be melt as temps well below -30 C. Once gone, it never returned to any similar values. 

note: a very unusual high of -3.8 C on Dec 23 2021, between two long cold spells. 

This site has rather complete data compared to YCB and YRB. The coldest month in Feb 2022 was based on complete data. 

^ July 2023 table value 8.2 C but 30-31 missing data, from hourlies available, est 4 C and 6 C dropping mean to 8.0. 

_____________________________________________________________

* Some temp data missing July 1-2 2016, mins are shown but not maxes, looked colder than the monthly mean of 8.4 so that is reduced here to 8.2 (est 3.5 1-2). 

^ Some temp data missing July 1-3, mins are available, and this time it looked a bit milder than the cold monthly mean of 4.3 so I adjusted up to 4.5 (Aug was complete and also 4.3).

^ Also the next July has three missing days 20-22 July, these may have been fairly warm as per Eureka (A) which is inlan (opened later in the study period) and runs a bit warmer in warm summer spells (probably a sea breeze effect closer to the fjord where Eureka climate station sits). I raised this data from 9.4 as reported to 9.7. There is some chance that the 19.0 max was broken then also (but the airport station while warmer than 19 in the missing days had its max on the same day as the 19.0). Considering the location and length of data period, I was fairly pleased with the continuity of data in general; as with other studies I am doing, the most recent years have more frequent missing days. Not sure if this is due to insufficient time for quality control to work through the data sets, or some kind of staffing issue that is getting worse with time, but it seems to affect a lot of different Canadian data sets.

*** This is the only example I saw in all data of a large one-day shift in snow depth that might be attributable to winds. No measurable snow was reported, the depths on both the previous and next day were under 12 cm, but a moderate southeast wind was reported. The other explanation might be a coding or data entry error. If not for this 26 cm reading on New Years Day then the maximum snow depth occurred on March 28th (17 cms). 

_____________________________

ANALYSIS of 2011-20 data

Although 2013 and 2014 were rather cold, this past nine years has seen mostly continuation of the slow warming trends of previous decades. There were at least three anomalously warm early winter periods (September into early October) in 2012, 2016 and 2019. This current winter 2019-20 started out rather feeble for cold, but converged on normal through December and has been quite cold in January (average was -39.7). The snow pack is currently very sparse, only 4 cm on the ground (updated on Feb 7th) but despite that it has been below -40 since the start of February and recently as cold as -48 C. (added later .. the season continued to record rather sparse snow cover and the summer was rather warm again at least in July, August was close to normal and in the past week as of 5 Sep the weather is close to freezing with no snow cover established yet.)

______________________________

SUMMARY of this study

Eureka represents a climate very close to the Greenland (and lesser Ellesmere Island-Devon Island-Axel Heiberg Island) ice caps and appears to be receiving more frequent incursions of milder air masses in winter, although not to the extent that the climate is radically different from the mid-20th century. These incursions do not happen every winter, or if they do happen in a given winter, they might only take place in say November or March, and not several different times. This seems to be the main reason why both average and extreme winter temperatures are gradually moderating, but make no mistake, this is still a very harsh arctic climate with full expectation of seeing -45 C days and -35 C months, most likely from January to March. A few anomalous events were noted throughout but this is a very predictable climate with long stretches of similar weather at various times of year. The summers also appear to be warming very slightly, and the onset of them has moved generally from late June into mid-June. A typical summer will not end suddenly but will fade out through August with a return of some snow and freezing daytime temperatures by late August. This can sometimes be muted and delayed well into September in a persistent southerly air flow bringing in saturated air from the Davis Sea (west of Greenland) that has temperatures near 2 or 3 C and dew points near 1 C. A cold drizzle falls from low clouds in this air flow, and it probably deposits wet snow on higher hills and the surrounding ice fields. The frequency of this sort of extended late summer appears to be rising in recent decades (from perhaps less than once a decade to 3-4 times now). Spring in most years seems to be a case where milder air masses slowly work their way into the region and sit over the decaying snow pack until it has all melted, then temperatures rise from around 5 C to 10-15 C with the bare ground exposed. But it does not appear that there is much of a shift in the weather itself after the melt is finished. Warmth depends mainly on hours of sunshine rather than any sort of air mass arrival. 

This is a precarious climate which could easily tilt to some other set of conditions, if for example winter snowfall increased in the region. It has seldom been much more than 30-40 cms in any recent winter. If for any reason heavier snow begins to fall more frequently, that could quite possibly stick around long enough to last through the brief summers. If on the other hand snow cover diminishes further, then summer could lengthen to something like late May to early September. Since Eureka is on a narrow inlet which is itself an extension of a relatively narrow channel between two large islands (Ellesmere and Axel Heiberg are roughly equivalent to Great Britain and Ireland in size) the oceanic influence (whether of open or frozen seas) is not large but it must play some role, so changes in ice cover might mean changes in precipitation. In what is almost a desert like rainfall profile, any increase would have significant effects on the environment. There seems little potential for precipitation to decrease at this location. 

 

 

 

Edited December 10, 2023 by Roger J Smith
new data for 2022 added

[Roger J Smith]

Frequency of temperature extremes for the full data set (76 years) at Eureka, Nunavut - Canada

 

1948-2023 ___ Winter min ______ 3.5 Dec, 18.5 Jan, 27.5 Feb, 26.5 Mar

1948-2023 ___ Coldest month ___ 7.0 Dec, 16.0 Jan, 29.5 Feb, 23.5 Mar

1948-2023 ___ Summer max ____ 11 Jun __ 56 Jul __ 9 Aug

1948-2023 ___ Warmest Months __ 0 Jun __ 72.5 Jul __ 3.5 Aug

Edited December 27, 2023 by Roger J Smith

[Midlands Ice Age]

Roger...

 Thank you very much for this extensive piece of work.

The writing up of which is superb and I appreciate the time that you have spent on it,

 

Eureka is a very interesting location, being one of the most northerly stations actually producing current actual data.

It is interesting that the ongoing warming trend seems to have eased during the last decade, as evidenced by the number of years that the lowest minimum has dropped below -50C (which actually rose during this decade), and also the number of times that the maximum exceeded 20C - which actually reduced.

I am a great believer in monitoring of the number of times that certain events happen (or the  time average length between these events) is probably a better method of determining trends rather than absolute values.

I am not suggesting that you perform yet another total analysis, but iit would be interesting to see any other data teased out. 

The above data is also representative of other anecdotal evidence and  'proxies' such as the fact that sea ice extent drop seems to have levelled off somewhat this last decade and also the very warm average temperatures reached by the CET record in the previous decade have not been repeated in the last 10 years,  DESPITE a very high CET recorded in 2014.

It is still too early to make any clear statements as to what is happening. Actual observations  do not seem to agree that the Arctic Ocean is rapidly becoming the 'inferno' that many climate model representation of the data appear to be suggesting.

Although, it is clear and  we all accept that some warming has occurred.

What happens in the next 10 years will be  decisive in determining where we are headed.

MIA

Oh, and welcome back to the UK!

 

 

 

 

 

Edited January 15, 2020 by Midlands Ice Age

[BornFromTheVoid]

Just downloaded the Eureka data to 2016, as that's the date that environment Canada provides monthly data for, but the warming probably continues after, as suggested by Roger.
Using a 10 year average, Eureka has warmed much more than the global average since 1948, up by 1.7C. It's also up 2.8C since the 70s. 

This warming is likely to be much greater if the early 20th century is included. Furthermore, Eureka is one of the slower warming stations in the Arctic because it's one of the regions that is still maintaining most of its sea ice through the summer.

The temperature largely reflects the global temperature trends, but amplified. As such, Eureka adds further evidence that Arctic amplification is real. 

[Roger J Smith]

So, first for MIA, thanks a lot, I am learning a lot about the details of this arctic warming from these studies. I will get back to that in a second paragraph below. But your comment "welcome back to the U.K." confused me as I am still a resident of British Columbia, Canada. Not sure if I said something to give you the idea that I had moved (back). 

As to the more general situation ... Eureka's records may terminate in 2016 in one area on-line but I was able to track them after a slight station re-organization. It wasn't really a move (except across the property, I gather). What happened was that the long-running station that has the name "Eureka" changed to Eureka climate in 2016. The location is very close to the old one, I think within a hundred feet of it. Meanwhile other obs were posted from some unchecked start date for Eureka airport which appears to be a few kms inland and higher up than these coastal locations I was tracking. They get slightly warmer summer temperatures once the snow has melted at Eureka A. I might delve into their stats to see if there's anything to be learned from the comparison. Like Dawson, a move of 10-20 km can make a bit of a difference. 

Now, as to this warming of the climate, which I accept is a real thing so no dispute about that ... I think it breaks down into two separate phenomena in the Canadian arctic. All three locations show signs of this. The first phenomenon is that winter has shortened by about 1-2 weeks at both ends. It starts earlier and lasts longer. By "summer" we are talking about the snow and frost-free season although within that season you can get occasional frosts and snowfalls. Then the second phenomenon is the occasional winter warmup. These used to be very rare in the 1940s to 1970s, perhaps even 1980s. Then they started to show up, not every winter, and sometimes two or three events per winter. 

Instead of staying in the -30s and -40s most of the time, the temperatures now have the tendency to rise far above normal into the range of -10 to +1 C, staying there for 2-5 days then gradually cooling back to the deep-freeze. Some of these warmings are accompanied by snowfalls, and others are not. I assume this is happening because low pressure areas from some southern origin make their way into the region. I've seen this happen in real time in recent winters. And I think it probably happens even more frequently in places like East Greenland, Jan Mayen and Svalbard, over towards Novaya Zemlya, so those places are getting a bigger temperature boost than the Canadian arctic. 

This still doesn't really answer the question of why this warming signal is happening. But it does point to air mass frequency rather than air mass modification as the prime driver of temperature increases. In terms of an AGW response or natural variability, it could be all one or all the other or some blend of them. Just spotting the phenomenon does not instantly provide an answer as to cause and effect. 

Later this year I might do a similar study for Iqualuit (formerly Frobisher Bay) in southeast Baffin Island. No idea what that might show, I try to maintain the element of surprise and not check the normals until I have done the study. But I am guessing the normals have come up like everywhere else "up north."

 

[Roger J Smith]

Here are some recent updates to these arctic data bases ... I will post the updated excel file of all data around 1st of November when this summer-autumn portion is more complete. This updates from the previous post about a year ago that took us through 2018 and 2019. 

 

Winter 2019-20 _______ cold mo __ min temp __ max snow __ snow change May _ last frost _ last snow

Cambridge Bay ______ -33.5 Feb*_ -43.5 Mar _ 25 cm Apr 2-15 _ 0 cm ______ June 16 ___ n/a ^^

Resolute# ___________ -32.5 Feb _ -44.5 Mar _ 29 cm Apr, May _ -7 cm _____ July 10 ___ June 7

* The data for Feb 2020 show 10th missing but all hourly data were in the daily portion of the data base so I took the extremes and factored them in -- it was a colder day than the monthly mean which shows up as -33.3 for 27 days of data, 10th was close to -39. This would adjust the monthly mean to -33.5 as shown. 

Cambridge Bay had a much colder May than in many recent years and considerable snow was on the ground into the first ten days of June (24 cm early June). The pack only melted completely by mid-June. As soon as the snow was gone the rest of summer 2020 seemed a bit warmer than average for the location. 

^^ I have marked "last snow"  at YCB as n/a (not available) because of frequent precip entries of "missing" combined with no measurable precip shown at any point in May, June or July. This is unusual for the climate region and I am not sure if it indicates a real absence of precip or not, making inquiries ... for now I cannot pinpoint any dates for last snow. Snow depth never increased in the melt period which can be an indirect indicator of snowfall. Temperature data were complete for these months. This problem persists to current time, trace snow was reported for 4 Sep with cold north winds, this may turn out to be the actual first snowfall date, but reports continue to give only trace amounts any day with non-zero precip. 

# The data for Resolute contain more frequent missing entries than I've seen in the past, and the values listed are both approximate and subject to change if I can find any sources for the missing days. Snow depths of 29 cm were reported on a number of different days in April and May but the entire season fluctuated between about 20 and 29 cm irregularly when reports were available. 

(June 2022 _ have added whatever data I could find, for YCB and YRB, 2021 and early 2022, with the disclaimer that missing data continues to degrade the data set).

 

Summer 2020 into autumn 2020 __ warm mo _ max temp _ first frost _ first snow _ first -20C

Cambridge Bay _______________10.9 Jul _ 23.2 Jul 2 __ Aug 29 _ n/a^^ ____ Oct 29

Resolute ______________________ 7.1 Jul __ 19.9 Jul 25 _ Aug 1 __ Aug 3 ____ Oct 22

^^ incomplete data makes determination difficult

 

 

winter 2020-2021 ________ cold month _ coldest day _ deep snow _ May 31 snow change _ last frost _ last snow

 

Cambridge Bay ______-33.6 Feb _ -43.9 Feb __ 37 cm Apr 27-May 2 _ 37 to 34 cm (-3) __  Jun 25 __ unk^ __ 

Resolute ____________-31 Feb,Mar _ -42.3 Feb _ 20 cm NOV _____ 18 to 8 cm (-10) ____July 21 __ unk^ __

^ unknown last snowfall date, only traces are reported in Apr to Jun despite heavy snow cover on ground that stayed unusually long (fully melted June 21). The last reported trace of snow was June 26th. June 2021 was unusually cold to almost the end. Mean 2.5 C. For YRB, same determination, later time frame (snow could have fallen in July, too much missing data). 

Note also some missing data YRB Feb, Mar, both months around -31 C and the extreme of -42.3 may have been outdone on some missing date. Have put in 20 cm NOV for max snow but most of the winter had reported snow depths between 17 and 20 cm. 

2021 ___________________ warm mo _ max temp _ first frost _ first snow _ first -20C

Cambridge Bay _______ 6.9 Jul _ 16.4 Jul 21 __ Sep 9 _ n/a^^ ____ Nov 9

Resolute _____________ est 4 Aug _ 13*Aug  _ Aug 16 _ Aug 20 ___ Oct 31

^^ first snow autumn 2022 no later than Oct 9, trace snowfall reports but steady buildup of ground cover suggests measurable amounts are for some reason being recorded as traces. There were frequent traces of snow in mid-September too, no reports of snow depths other than traces. 

* summer 2021 data very broken up by missing days, felt that Aug likely above 3 C website mean with the missing days in first week, also there could have been higher readings than 13.0 which was the highest captured on working days. But the season appeared generally rather cold compared to some recent summers. Some chance that earlier frost and snow happened but no close calls in reported data, a few missing days ??

 

winter 2021-2022 _______ cold month _ coldest day _ deep snow _ May 31 snow change _ last frost _ last snow

 

Cambridge Bay ______-33.5 Feb _ -41.9 Feb __ 32 cm Apr 15 _  29 to 28 cm (-1) __ tbd __ see note^ __ 

Resolute ______________-31 Feb __ -41 Feb ____ 16 cm late Feb _ 9 to 5 cm (-4) ___ tbd __ tbd

______________________________________________

^ Part of the data problem is that a lot of traces of snow are now being reported in late spring, with no measurable amounts; the temperatures suggest this may not be accurate so comparing this era with past data is suspect. The temperatures are probably more reliable though. Snow depth changes are inconclusive for determining veracity of small snowfall amounts and/or traces. They sometimes increase with only trace snowfalls but that can theoretically be from wind assisted inflow of ground snow. Meanwhile the last frost of late spring 2022 is yet to be determined (June 8th) and will be edited in before July 31st (last possible day before timetable reverses to first frost season). 

* Resolute coldest month and day are estimates due to the amount of missing data; the coldest day could have been lower. Snow cover reports intermittent, most of the winter had 12-16 cm when reports were made available. 

Any new data for Eureka and Dawson will be edited directly into their last tables (today). 

The summer of 2020 appeared to be a two-part variable scenario for Resolute, quite warm for that location in July with no snow events and little frost, then a much more wintry August with occasional wet snowfalls, and frequent light frosts. The mean temperature dropped from 7 in July to 3 in August. Cambridge Bay did not see such a sharp difference although August was a bit cooler than July there too (which is normal for the high arctic). 

The winter of 2020-21 was rather cold especially after mid-January. Summer 2021 was relatively cool.

The winter of 2021-22 started unusually late, the first -20C at YCB was very late (Nov 9th) compared to the average in late October and it was also rather late at YRB (Oct 31). 

Edited June 9, 2022 by Roger J Smith

[Roger J Smith]

Where possible, 2020 and 2021 (to date) stats have been added to the various files, in some cases edited in well back in the thread.

This past summer was rather chilly in the Canadian arctic, the means at all three locations studied seemed to be depressed by 1-2 degrees and extremes were not above the long-term medians. 2020 was a considerably warmer summer. The past winter 2020-21 was fairly severe by modern standards and it persisted into early April. 

It is possible that I may have to declare this study "completed" because the data reporting is becoming more and more intermittent for whatever reason, and I find it increasingly difficult to estimate accurate numbers for the various parameters being tracked with so many missing data points. 

That was becoming an issue at Toronto in the other study thread, back around 2012-2017, but it reversed with fewer missing data points. Toronto was easier to estimate missing values with a regional grid and hourly values sometimes available (just one or two of those missed and the day as a whole is declared missing even though the temperature extremes can be easily recovered). 

[LetItSnow!]

Absolutely fascinating read. As someone who is very much a person who loves sorting through data AND has a passion for weather and meteorology, I just want to say thank you for putting in the effort to post all this. It must take so incredibly long. It is much appreciated