Your December 2010 Statistics

[Optimus Prime]

December 2010 was exceptionally cold, by a long way the coldest on record (beating January 2010 at 1.5c) Maximum temperature on the 3rd was only -2.2c. Heavy snowfalls on the 18th led to 13cm of level snow (5 inches) Clearing skies allowed temperatures to fall to a new record low of -11.7c on the morning of the 20th. Otherwise a fairly dull month and rather dry.

Mean Maximum 3.3c; 4.8c below normal

Mean Min -1.5c; 4.6c below normal

Mean +0.9c; 4.7c below normal

Highest temperature; 29th at 8.8c

Lowest temperature; -11.7c on the 20th

Lowest Maximum -2.2c on the 3rd

Highest minimum 6.8c on the 29th

Edited December 31, 2010 by Optimus Prime

[in the vale]

My average is -2.4c

Avge daily max = 1.0c (highest = 9.9c)

Avge daily min = -7.2c (lowest = -13.4c)

Damned cold month all in all....

[Thundery wintry showers]

Statistics for Cleadon, Tyne and Wear:

Mean Max 2.6C (-4.8 )

Mean Min -2.9C (-5.4)

Mean -0.1C (-5.1)

* New record, smashing the previous coldest month (January 2010, mean 2.0C). Possibly the coldest month at the location since Feb 1963.

Highest max 8.1C (15th)

Lowest max -3.3C (20th)

Highest min 4.9C (11th)

Lowest min -10.3C (3rd)

The lowest max and min were both new site records, going back to 1993.

Precipitation: 49mm (86%)

Days of >= 1mm: 11

Wettest (snowiest?): 10mm (2nd)

Days of sleet or snow falling: 12

Days of >50% snow cover at 0900: 21

Days of small hail (<5mm diameter) 6

Days of large hail (>=5mm) 0

Days of fog at 0900: 0

Days of thunder: 0

The days of sleet/snow falling, snow lying and small hail were new high records for December.

A really exceptional month. The month began with two days of easterly winds and sunshine and snow showers, following on from the exceptionally cold north-easterlies at the end of November, and the snow depth reached 27cm on the 3rd, accompanied by a record low minimum of -10.3C. It was generally sunny from then until the 9th with a bit of snow late on the 6th, and continued exceptionally cold. The milder interlude on the 4th compacted the snow a bit but unlike further south it didn't turn especially icy.

It was milder between the 9th and 15th with a thaw, then severely cold weather returned on the 16th/17th and snow showers recurred between the 19th and 25th giving a maximum snow depth of 11cm. There was a surprising sleety shower at 8am on Christmas Day despite a temperature of -2C but this was enough to make it a bookies' white Christmas as well as one regarding lying snow. It turned milder and dull with a thaw from the 27th onwards but the 29th was a relatively bright hazy day.

Overall an exceptionally cold snowy month, and unlike in southern areas it was also exceptionally sunny, reflected by the fact that the negative anomaly was greater by night than by day- very unusual for a severe cold month this close to the North Sea coast.

[Osbourne One-Nil]

Great Asby:-

Average daily maximum; 0.9c

Highest daily maximum; 7.6c (16th)

Lowest daily maximum; -6.8c (8th)

Average daily minimum; -6.8c

Highest daily minimum; 2.5c (30th)

Lowest daily minimum; -14.5c (8th)

No. of air frosts; twenty-four

No. of ice days; seventeen

Monthly mean temperature; -3.0c

Total precipitation; 10.6mm

Days of snow falling; nine

Highest wind gust; 26mph (3rd)

[johnholmes]

December 2010 at Cantley and comparing to other ‘cold’ Decembers’ here

The mean temperature was 0.5C; the only December lower in this area (RAF Finningley 1943-1995 and Cantley 1 January 1997 on) is December 1981 with a value of -0.5C. The Central England Temperature (CET) for that month was +0.3C, making it the joint 7 coldest ever December in records going back to 1659. So December 2010 is certainly one to remember, bore your grandchildren with perhaps?

It was also the snowiest that I can find in December, other than 1981, with snow falling on 9 days and lying on 18 (pretty thinly after the first deep snowfall). 1981 had 12 and 20 respectively. But December 2010 had the greatest ever measured snow depth at 0900z in this area (see record period) on the 1st with 34cm, 18 of this fell the previous evening, making it by far the heaviest snowfall in November as well.

Air frost occurred on 20 occasions, 21 in 1981 but 8 Ice days were registered, the highest number apart from 12 in February 1947, with a consecutive run of 5 equalling the highest ever in any month, again December 1981. The lowest temperature of

-11.7C on 7 December has only been exceeded or equalled on 6 or 7 other occasions in any winter month.

.

The full data is available on my web site under Statistics-December, my own diary under My Climat data and Davis.

www.johnholmes-weather.co.uk

Please note that the rainfall amounts, daily and monthly, are not accurate due to snowfall and low temperatures.

[Evening thunder]

A very cold month overall with a mean temp over 5C below average, the coldest mean I have recorded although my records don't go back very far! (Oct 2007) But most likely the coldest for many years. The most notable features were probably the heavy snowfall on the 20th of about 18cm, bringing the total to about 25cm in places where there was no melt of the snow on the 17th and 18th, and also the min temp of -14.0C on the 25th, the lowest I have recorded. There was also a min of -12.7C on the 26th and the max on the 25th is the lowest I've recorded. The month avoided having a sub 0C mean due to the milder end to the month.

Statistics as recorded by my Davis VP2:

Note my weather station records its statistics midnight-midnight, however for highest/lowest overnight min and air frosts/nights below ?C I use the overnight period, otherwise high overnight mins can be missed if the temp then drops on that days evening, and 1 air frost with the temp falling below 0C before midnight would be recorded as 2 days of air frost.

Highest max: 10.4°C, 50.8°F (?th December)

Lowest max: -1.6°C, 29.1°F (25th December)

Highest overnight min: 6.8°C, 44.3°F (night of 28th-29th December)

Lowest overnight min: -14.0°C, 6.8°F ( night of 24th-25th December)

Highest daily mean: 8.3°C, 46.9°F (29th December)

Lowest daily mean: -9.6°C, 14.8°F (25th December)

Mean max: 4.1°C, 39.4°F

Mean min: -3.8°C, 25.1°F

Mean: 0.4°C, 32.7°F (roughly 5.3C below average!)

Air Frosts: 24

Mins below -5°C: 10

Mins below -10°c: 3

Ice Days: 3

Wettest day: 7.8mm (27th December)

Monthly total: 32.8mm (about 80mm below average) - Note much of the monthly total was made up of snow melt, and this might not reflect the true amount that fell as some snow may have blown out the stations rain gauge or the gauge became 'full'.

Days of falling sleet/snow: 5 (2nd, 17th, 18th, 19th, 20th)

Days of >50% snow cover at 09:00: 13 (2-3rd, 17th-27th)

Max Depth: about 10 inches, 25cm (20th)

Days of thunder heard: 1 - a not very bright flash and distant rumble during snowfall early on the 20th.

Average wind speed: 2.7mph

Max gust: 28mph (27th December)

Temperature and daily rainfall graph - note rainfall is unreliable on 2nd-3rd and 17th-26th due to snow melt in the gauge, often not on the day it fell. Also on some days 0.2mm of rain was frost melt.

Edited January 1, 2011 by StormMad26

[MP-R]

YATTON, Bristol

A very cold month overall. It's certainly the snowiest December I remember and although the cold spell from the 17th onwards had the same number of days with lying snow as that of the cold spell in January 2010, the lying snow at the start of the month brought the total number of snow-lying days to higher than that of January 2010. There were a few good sunny days but on the whole, the month was rather dull. There were plenty of ice days and record low minima for December that I have recorded. All in all, a month to remember for all the RIGHT reasons and just a shame the mild muck at the end had to bring the average to a positive value.

Average Max. Temp: 02.5C

Average Min. Temp: -02.0C

Monthly Average: 00.3C (03.3C below average) (3.2 in 2009, 3.9 in 2008)

Highest Max. Temp: 09.0C (29th)

Highest Min. Temp: 07.1C (28th/29th)

Lowest Max. Temp: -03.1C (20th)

Lowest Min. Temp: -09.0C (25th)

Wet Days: 06

Wettest Day: 07.5mm (04th)

Monthly Total: 25.8mm (83.3mm below average) (124.4mm in 2009, 85.0mm in 2008)

Snow Days: 05 (01st (tr), 17th (03.5cm), 18th (04.5cm), 20th (02.5cm), 21st (tr) )

Snowlie Days: 14 (01st, 02nd, 03rd, 17th, 18th, 19th, 20th, 21st, 22nd, 23rd, 24th, 25th, 26th, 27th)

Days with Hail: 00

Days with Thunder: 00

Days with Fog: 03

Days with Frost: 22

Days below 0C: 12

Edited January 1, 2011 by Michael Prys-Roberts

[Verglas]

Summary for December 2010

Temperature (°C):

Mean (1 minute) 3.3

Mean (min+max) 3.6

Mean Minimum 0.5

Mean Maximum 6.7

Minimum -4.1 day 21

Maximum 11.0 day 05

Highest Minimum 7.6 day 10

Lowest Maximum 0.0 day 20

Air frosts 16

Rainfall (mm):

Total for month 65.1

Wettest day 27.6 day 27

Rain days 16

Wind (mph):

Highest Gust 31.8 day 11

Average Speed 4.1

Wind Run 3018.7 miles

Gale days 0

Pressure (hPa):

Maximum 1041.2 day 15

Minimum 987.6 day 18

Days with snow falling 4

Days with snow lying at 0900 14

[Norrance]

Monthly mean here was -2.69c [Last Dec was +0.1c] so way colder. Must be a record cold month for here.

Coldest temp -14.2c on the 3rd.

Warmest 6.9c on the 11th.

Warmest day mean 4c on the 11th.

Coldest day mean -8.3c on the 22nd.

Best stat for me is: days with snow lying at 9AM = 31.

[damianslaw]

Great Asby:-

Average daily maximum; 0.9c

Highest daily maximum; 7.6c (16th)

Lowest daily maximum; -6.8c (8th)

Average daily minimum; -6.8c

Highest daily minimum; 2.5c (30th)

Lowest daily minimum; -14.5c (8th)

No. of air frosts; twenty-four

No. of ice days; seventeen

Monthly mean temperature; -3.0c

Total precipitation; 10.6mm

Days of snow falling; nine

Highest wind gust; 26mph (3rd)

Some fantastic cold stats here.. I don't have any for Windermere but I suspect they would have been very similiar though not quite so cold, I know our lowest min was about -11 degrees and we didn't see as many days with snow falling. However, we saw 18 ice days on a par with yourselves with a run of 10 ice days between the 17th-26th which caused the River Kent to freeze over in places the first time since winter 81/82.

It was the consistently very low minima which has made this month particularly notable. I remember travelling to Penrith on the 9th after the very cold night of the 8th and there was rime frost around Tebay and Penrith with maxes at noon of -5 degrees still. Another very cold day was the 20th travelling back from Newcastle where temps stuck around -5 degrees for most of my journey again around noon.

I hope January will be better in terms of amounts of snow for this part of the country - the one rather dissapointing aspect of Dec 2010 compared to may other parts of the country.

[BornFromTheVoid]

Ballyporeen, Co. Tipperary, Ireland

Mean Max 2.6C (2.63)

Mean Min -2.5C (-2.48)

Monthly mean 0.1C (0.07C)

Lowest Min -11.6C on the 24th

Lowest Max -4.9C on the 24th

Highest Max 10.9C on the 29th

Highest Min 8.9C on the 28th

15 days with snow cover

[paul tall]

Average Maximum Temperature : 2.6ºC

Average Minimum Temperature : -2.5ºC

Mean Temperature (Max+Min/2): 0.0ºC

High Temperature : 8.7ºC

Low Temperature : -10.6ºC

Days below 0ºC : 21 Days

Monthly Rainfall : 28 mm

Rain Days >1mm : 9 Days

Snow cover at 9am : 25 Days

Maximum snow depth 9am : 28cm

Coldest recorded here easily. Slightly disappointed to have not recorded a minus mean, most local places will have. Surprised to see Cleadon come out colder! Considering last January was 1.3 at Durham, 1.6 (by virtue of warmer nights) here, and 2.0 in Cleadon.

Ballyporeen, Co. Tipperary, Ireland

Mean Max 2.6C (2.63)

Mean Min -2.5C (-2.48)

Monthly mean 0.1C (0.07C)

Lowest Min -11.6C on the 24th

Lowest Max -4.9C on the 24th

Highest Max 10.9C on the 29th

Highest Min 8.9C on the 28th

15 days with snow cover

Those stats (I notice the ave max and min are exactly the same as mine) are absolutely incredible for the Republic of Ireland!

[Osbourne One-Nil]

Slightly disappointed to have not recorded a minus mean

Very surprising. I go to Newton Aycliffe quite a bit (big scheme at Whitworth Park means lots of council visits) and it's never what I'd call warm at the best of times.

[BornFromTheVoid]

Those stats (I notice the ave max and min are exactly the same as mine) are absolutely incredible for the Republic of Ireland!

Up to the 25th the mean was -1.6C, with a max of 1.2C and a min of -4.4C, but the the last 6 days were a good bit above average at 7.1C.

Practically every inland Met Eireann station averaged below 0C. Tis most likely the coldest December on record here.

[Thundery wintry showers]

Coldest recorded here easily. Slightly disappointed to have not recorded a minus mean, most local places will have. Surprised to see Cleadon come out colder! Considering last January was 1.3 at Durham, 1.6 (by virtue of warmer nights) here, and 2.0 in Cleadon.

This comes as a slight surprise to me too. The main reason for this was probably the spell of the 20th-26th December when Cleadon had a much deeper snow cover than Durham and Newton Aycliffe (8cm on the 20th, increasing to 11cm by the 24th) and this resulted in greater suppression of the temperatures whenever the wind wasn't off the North Sea, most notably the low maximum of -3.3C on the 20th.

In January 2010 the winds were frequently off the North Sea and Cleadon's snow cover was less deep than at Newton Aycliffe except on the 30th and 31st of the month, hence Cleadon being significantly warmer than Durham.

[reef]

Hedon, East Yorkshire.

December 2010

Warmest Max: 7.1°C (on 16/12/10)*

Coldest Max: -3.4°C (on 20/12/10 & 21/12/10)

Warmest Min: 3.4°C (on 31/12/10)*

Coldest Min: -11.4°C (on 21/12/10)*

Average Max: 2.1°C (-5.5°C Below 1971-2000 Average)*

Average Min: -2.4°C (-4.9°C Below 1971-2000 Average)*

Overall Average: -0.1°C (-5.2°C Below 1971-2000 Average)*

Rain: 53.2mm (72% Of Normal)

Wettest Day: 10th (15.2mm)

Air Frosts: 20 **

Sleet/Snow Falling: 13 days **

Snow lying at 0900: 24 days **

Dry Days: 11

Wet Days: 20

Days With Rain >1.0mm: 12

Thunderstorms: 2

Ice Days: 7 **

The coldest and snowiest December on record and the coldest month since February 1986. The month was consistently below average, but was separated by less cold weather in the second and final weeks. Only 9 days in the month had maxima above 4°C and 3 days of the month minima above 2°C. There were 8 days with minima below -5°C, more than the total in the previous 25 Decembers. The 7 ice days recorded equalled the number between February 1992 and November 2009.

The month started with north-easterly winds bringing heavy snow from a stream of showers. The max depth reached 27cm on the 4th, the deepest snow since January 1987. There was then a gradual thaw in the second week as it turned less cold from the west, though the compacted ice remained. It then turned exceptionally cold in the third week, with northerly winds bringing very low temperatures and further accumulations from snow showers. The 21st was a bitterly cold day as it remained clear and calm throughout, with a new December record low of -11.4°C and maximum of -3.4°C - the coldest since December 1995. The cold was less extreme into the christmas period but with snow showers on Christmas Eve night and a 8cm cover on the ground it was the first white christmas since 1995. The final week was then overcast and dull, with frequent fog patches and a gradual thaw.

Overall an exceptional month, setting a string of new December records.

* New Dec Low Record

** New Dec High Record

[Norrance]

From Aberfeldy, Perthshire.

Average max 0.4c

Average min -8c

17 ice days. Pretty cold despite a couple of plus 9c's towards the middle of the month.

Taken from the local Met O reporting station which is just above the valley floor at about 130 mtrs asl on the South facing side.

[The PIT]

For Sunny Sheffield

Ave 0.4c the 2nd coldest Dec ever with 0.2c being Dec 81.

Ave Max 2.6c again coldest since Dec 81

Ave Min -1.8c joint coldest with Dec 81

Rainfall 31.9mm the driest since 1963 which limped in with 18 mm

2nd Windiest day of the year with 56 mph being recorded on the 11th

40 cm of snow by the 2nd which shrank to 14cm by the 11th was quickly removed overnight due to the strong winds.

Although Snow returned on the 16th evaporation and contraction overnight meant no measurable depth by morning. The remaining Snow was mostly washed away in the Snow event that never was and any remaining snow gone by the 29th. Odd patch in the peak district though.

Also helped towards the coldest year since 1979 8.6C while 79 came in at 8.4c

Full details here including previous years http://www.sheffieldweather.co.uk/Weather%20Data.htm

Report of the month here http://www.sheffieldweather.co.uk/Last%20Months%20Report.htm

Edited January 2, 2011 by The PIT

[Andy Bown]

As with many other people, December 2010 was the coldest December I've ever recorded (started 2003), but not only was

it the coldest December - it was the coldest month I've recorded.

I am sure that but for a milder, although still average last 5 days, the mean would have been sub zero!

It was also a very dry month.

For Warminster, Wiltshire

Average max = 2.59c (Highest = 8.9c on 29 Dec)

Average min = -1.25c (Lowest = -9.0c on 27 Dec)

Mean = 0.66c

Dry days = 15

Precipitation days = 16 (of which wintry = 9)

Rainfall = 40mm

[TonyH]

December 2010, Lampeter, Wales

Exceptionally cold and snowy, mild last few days. Very dry.

An historical month. One of the coldest months since 1963, and the coldest December. 6 ice days, 23 air frosts, and snow lying on 20 days. The most startling figure being that 9 nights fell below -10c.

1^st– 9^th: Cold/ very cold with the snow cover from the end of November continuing. Snow flurries 1^st/2^nd became rain and sleet showers on the 3^rd/4^th. Some very severe frosts, down to as low as

-12.7c on the 3^rd . Sunny intervals, but sunny days 6^thand 8^th.

10^th– 11^th: Thaw, average temperatures and rather cloudy, with a little rain.

12^th- 15^th : Cold and mostly cloudy, mostly dry.

16^{th :} Near normal temperatures, showery, these wintry later.

17^th-26^th: Very cold, some very severe frosts. Heavy snow on the 17^th gave 19cm, the most seen since we moved to the area in 2002. This snow then lay on the ground until the 27^th. Further snow showers on the 18^th added slightly to the depth. Thereafter, mostly dry, and sunny 21^st-25^th, 4 successive ice days 22^nd-25^th, culminating in a truly exceptional Christmas Day having a minimum of -17.7c and maximum of -6.2c.

27^th: Sleet and rain at times with a steady thaw, a cold, raw day though.

28^th– 31^st:Mild and mostly cloudy, mist and fog at times. A rapid thaw would have cleared most of the snow by the 28^th.

Statistics

Total rainfall: 52.1mm

Wettest day: 17mm 16th

Rain days >0.2mm: 14

Wet days >1.0mm: 9

Days of heavy rain>10mm: 1

Mean temperature: -1.3c

Mean Max: +2.8c

Mean Min: -5.4c

High max: 10.8c 30th

Low max: -6.2c 25th

High min: 6.5c 29th

Low min: -17.7c 25th

Air frost: 23

Ground frost: 24

Ice days: 6

Mean RH: 92%

High RH: 100 various dates

Low RH: 78% 17th

Predominant wind directions: North

Mean wind speed: 0.3mph

Mean pressure: 1014mbar

Max pressure: 1041mbar 15th

Min pressure: 988mbar 18th

Days with:

Hail: 2

Sleet or snow: 11

Snow lying 0900: 20

Gale: 0

Thunder: 0

Fog: 5

Fog at 0900: 3

Edited January 4, 2011 by Tonyh

[Terminal Moraine]

The coldest December since 1981 here but in the valleys it was the coldest since 1890 due to much lower minima.

There were 19 days with a mean temp' below 0.0c, 1 fewer than in 1981 and 12 'ice days', equalling 1981.

It was the driest December since 1971 and the sunniest since 2007.

23 mornings with lying snow was the most on record, 1 more than in 1981 and 21 air frosts was 1 fewer than in 1981.

49cm of lying snow at 0900 on the 1st was the most on record in December and the most in any month since April 1981.

2010 was the coldest and driest year since 1996. 81 air frosts was the most since 1986 which also had 81 and 62 mornings with lying snow was the most since 1979.

The accumulated snowfall for the year was 139.8cm, the most since 1981 which had 152.1cm.

DECEMBER 2010.

Mean max'.....1.5c... ( -3.7c )

Mean min'....-2.1c.. ( -3.4c )

Highest max'...7.6c.. ( 29th )

Lowest max'....-3.5c.. ( 17th )

Lowest min'....-6.7c.. ( 20th )

Highest min'....4.6c.. ( 30th )

Lowest Grass min'..-12.0c.. ( 3rd )

Total Rainfall....40.3 mm...( 34% )

Wettest Day........8.6 mm... ( 27th )

Rain Days..........15

Total Sunshine......59.5 hrs... ( 112% )

Sunniest Day........6.2 hrs..... ( 6th )

Days sleet/snow falling... 15

Snow lying at 0900.........23

Air Frosts.................21

Ground Frosts..............24

Days with Hail..............2

[Stargazer]

My statistics for central Reading in December 2010:

Average maximum: 3.0

Average minimum: -1.0

Average for month: 1.0

Highest maximum: 8.2 (December 11)

Lowest maximum: -1.9 (2) - the lowest recorded since I moved here in 2002

Highest minimum: 6.6 (30)

Lowest minimum: -4.5 (19) - also the lowest recorded since I moved here in 2002

Air frosts: 21

Ice days: 5

Rainfall: no data available for this site; Reading University shows around 15mm for the month, which is very dry - most of this is from two snowfalls on the 1st and 18th.

As with the rest of the UK, an exceptionally cold month - probably the coldest in Reading since February 1986 - with day and night time temperatures around 5 deg C colder than the long-term average. There was somewhat less snowfall here than in many parts of the UK - around 2cm of lying snow on the 1st, which had melted by the 3rd, and around 6cm on the 18th that thawed slightly each day and finally disappeared by the 27th.

Edited January 6, 2011 by Stargazer

[Norrance]

Here are the Met O Regional values for Dec2010.

How do they compare with your own records. For me they are pretty close. http://www.metoffice.gov.uk/climate/uk/2010/december/averages.html

[Stargazer]

My statistics for central Reading in December 2010 (with a correction to the lowest minimum temperature):

Average maximum: 3.0

Average minimum: -1.0

Average for month: 1.0

Highest maximum: 8.2 (December 11)

Lowest maximum: -1.9 (2) - the lowest recorded since I moved here in 2002

Highest minimum: 6.6 (30)

Lowest minimum: -9.4 (19) - also the lowest recorded since I moved here in 2002

Air frosts: 21

Ice days: 5

Rainfall: no data available for this site; Reading University shows around 15mm for the month, which is very dry - most of this is from two snowfalls on the 1st and 18th.

As with the rest of the UK, an exceptionally cold month - probably the coldest in Reading since February 1986 - with day and night time temperatures around 5 deg C colder than the long-term average. There was somewhat less snowfall here than in many parts of the UK - around 2cm of lying snow on the 1st, which had melted by the 3rd, and around 6cm on the 18th that thawed slightly each day and finally disappeared by the 27th.

In reply to Norrance's post, looks like the maxima here were typical for southern England but, not surprisingly for a town centre location, minima were considerably higher.