This thread is for all comments, discussion, and analysis of temperatures in the UK during May, with particular emphasis on the Central England Temperature (CET), for the simple reason that it is the longest-running temperature series in the world with over 360 years of data. But you can comment on any interesting temperature statistics or data from across the UK, including your own backyard. 

For those taking part in the competition, all CET predictions for May should be sent directly to me via the forum private message system. Please do not post them directly into the thread.  

Historic CET summary for May

1981-2010 11.66C (30 years)   

1991-2020 11.90C (30 years)  

2001-2020 12.02C (last 20 years)  

Last year May was above average at 12.5C. The prior year was slightly below average with 11.2C. 2017 and 2018 were both very warm and above 13C. We have had a few cold May's in recent years, 10.8C in 2015, 10.4C in 2013, and 10.7C in 2010. 

Here is a chart of the May CET for all years since 1961  

Direct link to a larger version of the chart

Current model output    

850s start the month below average. After the first week there is a lot of scatter and the ENS mean is around average. 

GEFS 850s 

https://www.wetterzentrale.de/de/show_diagrams.php?geoid=49069&model=gfs&var=2&run=99&lid=ENS&bw=

https://www.wetterzentrale.de/de/show_diagrams.php?geoid=49069&model=gfs&var=5&run=99&lid=ENS&bw=

ECM (de Bilt) also looks cool although there are a number of much warmer runs in the second week of May

http://cdn.knmi.nl/knmi/map/page/weer/waarschuwingen_verwachtingen/ensemble/detail/ensemble-verwachtingen-detail10.png

Met Office contingency planners outlook  

https://www.metoffice.gov.uk/binaries/content/assets/metofficegovuk/pdf/business/public-sector/civil-contingency/3moutlook-mjj-v1.pdf

The 3-month outlook is still a 35% chance of warmer than average conditions (which is 1.8x normal and the same as last month). Cooler conditions are 0.5x normal probability. Didn't exactly work out well in April!

For May there is a 55% chance of near-normal temperatures and 30% chance of above-average temperatures. 

Lower than average SSTs around the UK at present favour cooler than average conditions.

Hadley

6.6c to the 1st

2.8c below the 61 to 90 average
4.0c below the 81 to 10 average

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Current high this month 6.6c on the 1st
Current low this month 6.6c on the 1st

Met Office Hadley 6.6c Anomaly -2.8c provisional to 1st.
Metcheck 5.38c Anomaly -6.03c
Netweather 6.93c Anomaly -4.38c
Peasedown St John 6.93c Anomaly -8.37c.

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The CET minimum of April 2021 was 1.0C but the period 3rd April-2nd May 2021 CET minimum is provisionally 0.7C!

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Met Office Hadley        6.7c      Anomaly     -2.7c provisional to 2dnd

Metcheck                     6.58c    Anomaly     -4.82c

Netweather                  7.36c    Anomaly     -3.95c

Peasedown St John     6.6c     Anomaly      -5.8c.                 

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First look at the May CET tracker

The very cold weather continues for the first week of the month. Signs of a pattern change from next weekend as things could potentially turn milder and above average. 

Chart 1

Chart 2

Here is the list of predictions for May

Chart 1

I see Gusty's taking the "sh*t or bust" route 

 

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Here is the list of predictions for May

IMAGE. Members enable at bottom of page

Chart 1

Looking at the latest GFS have we all gone to high again. 

1816 again anyone?

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Met Office Hadley        7.2c      Anomaly      -2.4c provisional to 3rd

Metcheck                     6.98c    Anomaly      -4.42c

Netweather                  7.73c    Anomaly      -3.58c

Peasedown St John     7.4c      Anomaly      -5.0c.

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Looking at the latest GFS have we all gone to high again. 

1816 again anyone?

 

I must say I was quite shocked to be so far down the list with 10.5c.

I thought we'd have a few more takers for well below average after the April we've just had and the frankly dismal charts for the next week or so.

May hasn't really been given a proper cold edition since the exceptional 1996, and that year would have been even more exceptional were it not for the heatwave at its very conclusion. We are going to need a significantly improved prognosis in the second half to avoid a similar calamity this year at this rate 

 

 

I must say I was quite shocked to be so far down the list with 10.5c.

I thought we'd have a few more takers for well below average after the April we've just had and the frankly dismal charts for the next week or so.

May hasn't really been given a proper cold edition since the exceptional 1996, and that year would have been even more exceptional were it not for the heatwave at its very conclusion. We are going to need a significantly improved prognosis in the second half to avoid a similar calamity this year at this rate 

Iam also suprised to be so far down the list to! It would be interesting to know why so many have so high? I really think this May is going to be a shocker as well as the whole of summer 2021.

 

Iam also suprised to be so far down the list to! It would be interesting to know why so many have so high? I really think this May is going to be a shocker as well as the whole of summer 2021.

I went average purely because it seems to be very difficult getting below average months these days and getting 2 in a row seemed unlikely. We're at that time of year where a cool start can easily be overcome by a few days of very high temps and it wouldn't surprise me to see some real warmth drawn up later on. 

 

 

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I suspect the 30 day CET running mean is actually less than the equivalent period in 1986.

 

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I see Gusty's taking the "sh*t or bust" route 

 

 We know the answer to that already ! 

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Met Office Hadley       7.4c     Anomaly     -2.2c provisional to the 4th

Metcheck                    6.81c   Anomaly     -4.60c

Netweather                 7.84c   Anomaly     -3.47c

Peasedown St John    7.6c     Anomaly     -4.8c.

 

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I think May is going to be a cold one but wouldn't be so sure the trend will extend into the summer months. The cold springs 1996 and 2013 were both followed by pretty decent summers ; if anything I tend to worry if we get too much warm weather too early that we've "used up our luck" for the year and will be punished with a dreadful summer (2007 being the classic example of this)

 I went average purely because it seems to be very difficult getting below average months these days and getting 2 in a row seemed unlikely. We're at that time of year where a cool start can easily be overcome by a few days of very high temps and it wouldn't surprise me to see some real warmth drawn up later on. 

I went just above average but my thinking was exactly the same as yours.  

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I went just above average but my thinking was exactly the same as yours.  

I went just below but the thinking was the same. Then again, I thought the same for April....

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I went just below but the thinking was the same. Then again, I thought the same for April....

My thinking was the same for April too but you did considerably better than I did.  You have more to lose than I have this month.  Good luck.   

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