20 replies to this topic

[Andy Bown]

I was wondering, due to the potential for a temperature of 17c later this week and the earlier tempertaures this month of around
-18c, what the greatest temperature contrast is within a single month in the UK.

I would expect a month like April to have a greater contrast than this month's possible 35c, but wondered if anybody knows of any
links to such statistics?

Taking it further, how about the greatest temperature contrast in a winter (Dec 1 - Feb 29) month?

Thank you.

[Thundery wintry showers]

I can't locate any definites but I can think of other months that had a range of around 35C.

The Mays of 1990, 1992, 1995 and 2010 all produced ranges of around 35C. 1990 is perhaps a surprising case as it was a consistently warm month but there were a couple of notable frosts in places near the end of the month, while those of 1992, 1995 and 2010 all had a cold snap in the second week. In the summer June 1975 must surely have produced a similar range, as more recently did June 2005 (frosts on the night of the 6th/7th and then up into the low 30s in the south on the 19th).

January 1958 is a contender in the winter quarter as we had a notably cold snowy northerly from the 19th-25th and then an exceptionally warm southerly after the 25th during which it locally reached 18.3C.

There are also March/April contenders, e.g. March 1965 started with exceptionally cold north-easterlies but on the 29th it got to 25C at Whitby.

[johnholmes]

June 1975 is perhaps one in terms of the change from low to high in less than a week?

25C for RAF Finningley
3.1C Mn on 1st to 25.6 C Mx on 7th with 6 out of the next 7 days over 25C, absolute Mx in that period 28.2C

Edited by johnholmes, 20 February 2012 - 14:19 .

[SNOW_JOKE]

April 2011 I remember well, as the start of the month the final stages of the SSW event was starting ebb away, then came the dry-spell and exceptionally warm temperatures which was like a 'hair-dryer' and resulted in Irelands biggest wildfires for some time, aswell as some breaking out across the N.Pennines and Yorkshire.

A maximum temperature of 27.8 °C was recorded at Wisley, Surrey on 23rd. A minimum temperature of –5.4 °C was recorded at Tulloch Bridge, Highland early on 26th. In the 24 hours ending at 0900 on 6th, 80.7 mm of rainfall was recorded at Achnagart, Highland. In marked contrast, some places across the eastern half of England recorded less than 1 mm of rain in the whole month. A wind gust of 71 mph was recorded at Blackford Hill, Edinburgh on 2nd.

[March Blizzard]

Not sure if you mean in a single calender month or the overall temperature disparity for any given month of the year. I found these stats on the Met Office website. Not sure how accurate they are:

Jan - High: 18.3C, Low: -27.2C, Variation: 45.5C
Feb - High: 19.7C, Low: -27.2C, Variation: 46.9C
Mar - High: 25.6C, Low: -22.8C, Variation: 48.4C
Apr - High: 29.4C, Low: -15.0C, Variation: 44.6C
May - High: 32.8C, Low: -9.4C, Variation: 42.2C
Jun - High: 35.6C, Low: -5.6C, Variation: 41.2C
Jul - High: 36.5C, Low: -2.5C, Variation: 39.0C
Aug - High: 38.5C, Low: -4.6C, Variation: 43.1C
Sep - High: 35.6C, Low: -6.7C, Variation: 42.3C
Oct - High: 29.9C, Low: -11.7C, Variation: 41.6C
Nov - High: 21.7C, Low: -23.3C, Variation: 45.0C
Dec - High: 18.3C, Low: -27.2C, Variation: 45.6C

It appears that March actually experiences the biggest extremes in temperatures throughout the year, July the least. It doesn't really surprise me to be honest, March can have perishingly cold nights on par with the winter months, but can also experience quite balmy day time temperatures too, especially when April is knocking on it's door.

[Andy Bown]

March Blizzard, on 20 February 2012 - 15:30 , said:

Not sure if you mean in a single calender month or the overall temperature disparity for any given month of the year:

I mean within a single calendar month.

Thanks for all replies so far.

[Mr_Data]

Three examples that haven't been mentioned but December 1981 January 1982 and December 1995 had large temperature contrasts

December 1981: Dyce recorded 15.0C; Shawbury: -25.2C A difference of 40.2C
January 1982: Leuchars: 13.7C; Braemar: -27.2C, a difference of 40.9C
December 1995: Hastings: 14.5C; Braemar: -27.2C A difference of 41.7C

and the maxima I stated there are probably not the absolute maximum for those months.

[Mr_Data]

Thundery wintry showers, on 20 February 2012 - 13:58 , said:

.

March 1965 started with exceptionally cold north-easterlies but on the 29th it got to 25C at Whitby.

-21.7C on the 3rd March 1965; 25.0C on the 29th March 1965

A difference of 46.7C

[Bishop Brennan]

An absolutely fascinating thread. It's funny, I was thinking of asking the same question, but you bat me to it Andy!

The temperature differences for March 1965 are extraordinary.

Bish

[Andy Bown]

Very glad to have beaten you to it BB, lol !! I was thinking about it while out working this morning.

Mr_Data, on 20 February 2012 - 18:19 , said:

Three examples that haven't been mentioned but December 1981 January 1982 and December 1995 had large temperature contrasts

December 1981: Dyce recorded 15.0C; Shawbury: -25.2C A difference of 40.2C
January 1982: Leuchars: 13.7C; Braemar: -27.2C, a difference of 40.9C
December 1995: Hastings: 14.5C; Braemar: -27.2C A difference of 41.7C

and the maxima I stated there are probably not the absolute maximum for those months.

Mr_Data, on 20 February 2012 - 18:22 , said:

-21.7C on the 3rd March 1965; 25.0C on the 29th March 1965

A difference of 46.7C

Goodness, thank you Kevin. It's going to be interesting come Thursday afternoon to see what contrast we end up with.

[reef]

Large extremes in one month are pretty rare in this location due to having the Humber Estuary 2 miles to the south-west and North Sea 9 miles to the north-east. The largest extreme actually came in August 1990:

Max of 34.0C on the 3rd and a min of 7.1C on the 18th. A difference of 26.9C.

In Autumn, the largest extreme actually came in October 2011 with a max of 27.3C (1st) and min of 2.2C (20th).

A full range of the largest extremes here from 1981-2012 (Min/Max (Diff) and year):

JAN: -10.0C / 11.0C (21.0C): 1982
FEB: -6.6C / 13.9C (20.5C): 1991
MAR: -5.4C / 16.7C (22.1C): 2006
APR: -2.6C / 21.3C (23.9C): 1996
MAY: 0.1C / 26.7C (26.6C): 2010
JUN: 4.4C / 29.5C (25.1C): 2005
JUL: 7.7C / 30.2C (22.5C): 1996
AUG: 7.1C / 34.0C (26.9C): 1990
SEP: 4.0C / 26.1C (22.1C): 2003
OCT: 2.2C / 27.3C (25.1C): 2011
NOV: -6.8C / 17.3C (24.1C): 2010
DEC: -10.9C / 9.5C (20.4C): 1995

ANN: -10.9C / 30.3C (41.2C): 1995

[Interitus]

Andy Bown, on 20 February 2012 - 13:51 , said:

I was wondering, due to the potential for a temperature of 17c later this week and the earlier tempertaures this month of around
-18c, what the greatest temperature contrast is within a single month in the UK.

AFAIK -15.6 is the low point not -18 so the range is only going to be in the low 30s

[Interitus]

Mr_Data, on 20 February 2012 - 18:19 , said:

Three examples that haven't been mentioned but December 1981 January 1982 and December 1995 had large temperature contrasts

December 1981: Dyce recorded 15.0C; Shawbury: -25.2C A difference of 40.2C
January 1982: Leuchars: 13.7C; Braemar: -27.2C, a difference of 40.9C
December 1995: Hastings: 14.5C; Braemar: -27.2C A difference of 41.7C

and the maxima I stated there are probably not the absolute maximum for those months.

The Dec 95 min of -27.2 was Altnaharra of course.

[AderynCoch]

I'm pretty confident March 1965 takes the crown here - not only is March a good month for transitions but in 1965 it contained the one of the highest March temperatures on record (the only other years to have seen 25C in March are 1929 and 1968) and one of the coldest March temperatures (I can't think of many other Marches which have dropped below -20C - only 1947, 1958 and 2001 spring to mind).

On the other end of the scale, I wonder what the month with the lowest temperature range is?

[Aaron]

I wonder if somewhere in Lincolnshire that recorded -15C earlier on this month could reach 16/17c this week.. that'd be impressive

[Terminal Moraine]

AderynCoch, on 21 February 2012 - 04:28 , said:

On the other end of the scale, I wonder what the month with the lowest temperature range is?

I've no idea what the national record is for the least temperature range but here I've recorded a number of months with a range of less than 11c. Smallest of all were February 2010 with a range of 9.1c ( -3.2/ 5.9c ) and February 1986 with a monthly range of 8.8c ( -8.1/ 0.7c )
For a summer month July 1988 was top of the list with a range of 11.5c ( 7.0/ 18.5c )

Edited by Terminal Moraine, 21 February 2012 - 09:22 .

[Thundery wintry showers]

February 2010 won't be a contender for "lowest temperature range" at a national scale because parts of Scotland had notably low minima late on in the month, but certainly at a local level it was notable for low temperature ranges. Here at Cleadon the range of maximum temperatures was exceptionally low, from a low of 2.6C to a high of 6.8C, though the absolute monthly minimum of -4.6C probably prevented the max-min range from approaching any records.

July 1988 has to be a contender though as it was characterised by remarkably consistent but unexceptional cold, and the negative temperature anomaly was much greater by day than by night, even in the parts of eastern Scotland and north-east England that managed close to average sunshine totals. At Lancaster the monthly max was 18.7C and the monthly min 8.9C (amusingly both recorded on the same day). The national maximum temperature must have been exceptionally low too, e.g. Tutiempo.net has Heathrow's absolute maximum as 23C.

[Aaron]

So the lowest temperature this month was -16C (rounded) and the highest was 19C (rounded), so that's a range of 35C!! Not bad

[Terminal Moraine]

The temperature range in February now stands at 21.2c here, the largest I've recorded for the month in the last 35 years and just beating the range of 20.8c in Feb' 2008.

[johnholmes]

27.0C here with a low of -8.4 and a high of 18.6C
but no idea what the largest variation is, something I've never noted specifically before