Diurnal temperature variation watch

[March Blizzard]

We're at that time of year again when the difference in temperature between day and night can be notable. Please use this thread to log/discuss your own or other diurnal ranges.

Eskdalemuir: -4.4C at 6am, up to 10.6C at 2pm

Keswick: -4.2C at 6am, up to 12.7C at 2pm

Shap: -7.0C at 7am, up to 9.2C at 2pm

Carlisle: -3.5C at 4am, up to 10.7C at 2pm

Strathallan: -4.2C at 7am, up to 11.9C at 1pm

[NorthYorksWeather]

Low of -5.0c this morning then a max of 11.6c. Diurnal range of 16.6c which is impressive!

[March Blizzard]

Thanks for your post, Vizzy. You've done quite well, I'd imagine that's one of the biggest ranges in the country today.

[March Blizzard]

Some very big ranges today;

Benson -3.7C at 7am, 15.3C at 2pm = 19C

Trawsgoed -2.8C at 5am, 16.8C at 2pm = 19.6C

Capel Curig -4.9C at 7am, 13.1C at 3pm = 18C

Just to name a few.

[Bottesford]

+0.3 to 6.5c... hmm not exactly noteworthy here!

[March Blizzard]

+0.3 to 6.5c... hmm not exactly noteworthy here!

I would say it is noteworthy for it's narrow range! Some massive differences across the country today.

[Richie V]

Minus 3.3 to plus 6.4 today. Already fallen back to plus 2.2 now and the mist is coming in.

[reef]

-1.4C to 5.2C here, a small range due to the persistent fog and actually a pretty cold day for mid-winter never mind early March.

[Bottesford]

I would say it is noteworthy for it's narrow range! Some massive differences across the country today.

Ah but not as narrow as vast chunks of Jan & Feb with ranges like +1.2 to +2.1c a typical example for days last week.

[TonyH]

21.5c range today, from -5.5c to 16c:

Edited March 5, 2013 by TonyH

[TonyH]

On weatheronline the min for Trawsgoed today was -4c and max 18c making a 22c range!

http://www.weatheronline.co.uk/weather/maps/current?LANG=en&UP=0&R=310&TYP=tmax&ART=tabelle&LANG=en&DATE=1362517200&KEY=UK&LAND=UK&CONT=ukuk&SORT=3&SI=mph&CEL=C&UD=0

[March Blizzard]

On weatheronline the min for Trawsgoed today was -4c and max 18c making a 22c range!

http://www.weatheronline.co.uk/weather/maps/current?LANG=en&UP=0&R=310&TYP=tmax&ART=tabelle&LANG=en&DATE=1362517200&KEY=UK&LAND=UK&CONT=ukuk&SORT=3&SI=mph&CEL=C&UD=0

That's almost as large a variation as late March last year in Scotland!

[Stargazer]

-1.0 to 16.5 here yesterday, not bad for an urban location that's not particularly frost prone. The nearest official station, at Reading University, recorded -1.0 to 16.2.

[greybing]

Does this big diurnal/nocturnal difference in temperature happen partly because of the relatively long times of both night and day .At the moment I think it's 11.18 minutes of our turn of sun light in london and 12.42 minutes of no sun.Why does the temperature drop quicker this time of year here.For example in december when the nights are way longer than the days there could be a day when there is aa 2 celcius maximum and the subsequent snowless,calm ,clear conditions of the night time end up aiding the minimum to -3 or -4c,a drop 5 or 6c.Yet now were getting form 14 to sub zero. Please indulge my ignorance and hopefully I and others can find out,thanks.

Edited March 6, 2013 by greybing

[March Blizzard]

Does this big diurnal/nocturnal difference in temperature happen partly because of the relatively long times of both night and day .At the moment I think it's 11.18 minutes of our turn of sun light in london and 12.42 minutes of no sun.Why does the temperature drop quicker this time of year here.For example in december when the nights are way longer than the days there could be a day when there is aa 2 celcius maximum and the subsequent snowless,calm ,clear conditions of the night time end up aiding the minimum to -3 or -4c,a drop 5 or 6c.Yet now were getting form 14 to sub zero. Please indulge my ignorance and hopefully I and others can find out,thanks.

I'm unsure myself but your "half and half" idea in terms of length of day and night seems logical, it allows enough time for temperatures to rise and then fall without going too far either way. However, I think the main cause is humidity, or rather the lack of it. March is often a "dry" month so when calm, clear conditions materialise at this time of year there is reletively little humidity to "hold up" the temperatures overnight, so they drop sharply after sunset.

Naturally, deserts and other arid areas see the greatest diurnal ranges. Places like the Gobi desert and the Dakotas in the US can see some huge ranges. Conversely, very humid places like Singapore have very narrow ranges.

Edited March 6, 2013 by March Blizzard

[Richard2901]

Last Wednesday under a nice sunny high I managed a range of 13.7C (-3.0C to 10.7C)

Today under dire easterlies an extremely low range of 1.3C (3.8C to 5.1C)

[TonyH]

I'm unsure myself but your "half and half" idea in terms of length of day and night seems logical, it allows enough time for temperatures to rise and then fall without going too far either way. However, I think the main cause is humidity, or rather the lack of it. March is often a "dry" month so when calm, clear conditions materialise at this time of year there is reletively little humidity to "hold up" the temperatures overnight, so they drop sharply after sunset.

Naturally, deserts and other arid areas see the greatest diurnal ranges. Places like the Gobi desert and the Dakotas in the US can see some huge ranges. Conversely, very humid places like Singapore have very narrow ranges.

The West Wales desert effect, well it has been dry for 3 weeks!

[Interitus]

On weatheronline the min for Trawsgoed today was -4c and max 18c making a 22c range!

http://www.weatheron...=mph&CEL=C&UD=0

Those figures are rounded, the SYNOP values were -3.5°C and 17.5°C for a total of 21°C so less than your range.

[TonyH]

Those figures are rounded, the SYNOP values were -3.5°C and 17.5°C for a total of 21°C so less than your range.

Where might we find the SYNOP values? Thanks.

[Interitus]

Ogimet is good - lots of options but for example http://www.ogimet.com/ranking.phtml.en - select the region/country and date/time required and increase the number of stations if necessary.

Here is the UK yesterday to 6pm http://www.ogimet.co...ra=18&Send=send

Click on a station to bring up the last 30 days data - Trawscoed http://www.ogimet.co...&min=0&ndays=30

Clicking on an individual date here gives the details for that day which is helpful when sometimes there can be discrepancies in temperature/precipitation depending on reporting hour and the fields in the SYNOP report.

[hillbilly]

i believe the record is around 29 deg

[March Blizzard]

i believe the record is around 29 deg

There seems to be a bit of ambiguity regarding the actual largest diurnal range. I've heard Altnaharra in December, Redhill in August and Perthshire in May as contenders. If anyone knows for sure i'd be glad to hear it.

[Stargazer]

I answer to greybing's question of whether it's the day/night ratio that affects the diurnal temperature variation,I don't think this the case. It seems that the time of year with the biggest diurnal variations actually depends somewhat on location - hence the contenders for all-time maximum recording their highest ranges at different times of year. In general, spring and summer have higher diurnal variations and autumn the lowest.

Here in Reading, for example, the highest variations tend to be during hot spells in summer when a night time minimum of around 12C can occasionally be followed by a daytime maximum of 32+. July 17 and 18 2006 were similar to this here. But up the road in Benson, a notable frost hollow, it is possible to get such variations in winter too because of occasional exceptionally cold winter nights (in January 2010 we had minima around -7 in Reading and -18 in Benson on the same night).

[greybing]

Thank you for your responses though I am still a little in the dark,ha...I did look online for a definative answer and didn't so asked the community here.Again thanks .

[coram]

Thank you for your responses though I am still a little in the dark,ha...I did look online for a definative answer and didn't so asked the community here.Again thanks .

From memory the biggest diurnal recorded in the UK is 29C (-7C to 22C). I think this occurred in May in the south-east Highlands.