This thread is for all comments, discussion, and analysis of temperatures in the UK during July, 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 July 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 July

1981-2010 16.71C (30 years)   

1991-2020 16.79C (30 years)  

2001-2020 16.82C (last 20 years)  

Last year July was chilly at 15.7C. Three years ago was very warm at 19.1C.

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

Direct link to a larger version of the chart

Current model output     

850 temperatures are slightly above average after the first couple of days of the month. However, T2m temperatures look uninspiring. Close to average at best.

GEFS

https://www.wetterzentrale.de/de/show_diagrams.php?geoid=49069&model=gfs&var=2&run=00&lid=ENS&bw=

https://www.wetterzentrale.de/de/show_diagrams.php?geoid=49069&model=gfs&var=5&run=0&lid=ENS&bw=

ECM (de Bilt) also looks average at best

http://www.knmi.nl/exp/pluim/Data/PLUIM_06260_NWT.png

Met Office contingency planners outlook  

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

No strong signal this month. Close to average seems the most likely scenario.

Thanks. This needs stickying! 

July already!  What will this month do?

Thanks. This needs stickying! 

Just done it.

Met Office Hadley        16.7c        Anomaly      1.0c  provisional to 1st

Metcheck                     14.36c      Anomaly      -2.11c

Netweather                  15.76c      Anomaly       0.75c

Peasedown St John     15.57c      Anomaly      -1.28c.    

Here are the predictions for July

Table

First look at the July CET tracker. First half of the month looking very average overall.

Table 1

Table 2

First look at the July CET tracker. First half of the month looking very average overall.

IMAGE. Members enable at bottom of page

Table 1

IMAGE. Members enable at bottom of page

Table 2

Thanks GW. I’m banking on a week or so of quite hot weather in the second half amongst a further week of averagenesss. 

Met Office Hadley          17.3c        Anomaly        1.7c provisional to 2nd

Metcheck                       15.53c       Anomaly        -0.94c

Netweather                    16.59c       Anomaly        0.1c 

Peasedown St John      16.55c      Anomaly        -0.3c.           

This month's CET will be heavily steered by whether an active MJO event or similar moves eastward from the Indian Ocean to the tropical Pacific in the coming fortnight.

If this happens, it will increasingly push weather patterns toward ones that favour ridges moving generally east-northeastward across western & northern parts of Europe. Typically very warm overall for the CET zone, with some hot spells in the mix. Given the alignment with time of peak overall heat build across the mid-latitudes, this has the potential to raise the CET considerably.

If it doesn't, we're unlikely to see any protracted particularly warm spells. Probably not cool ones either, just variable conditions. I'd estimate a final CET in the high 15s to mid-16s in that scenario.

At the turn of the month, there was good model consensus on the MJO propagating, albeit at uncertain speed.

Just a few days in, the consensus has suddenly weakened considerably (...but of course), with ECMWF's ensemble prediction system completely undecided. The N. American equivalent, GEFS, remain bullish. Hope for those in the upper reaches of this month's estimation spread lies with them!

Met Office Hadley         17.5c        Anomaly        2.1c provisional to 3rd

Metcheck                      15.92c      Anomaly         -0.54c

Netweather                   16.85c      Anomaly         0.36c

Peasdown St John       16.65c      Anomaly      -0.2c.  

Met Office Hadley         17.5c        Anomaly       2.0c Provisional to 4th

Metcheck                      15.89c      Anomaly       -0.57c

Netweather                   16.85c      Anomaly       0.90c

Peasedown St John     16.4c       Anomaly      -0.45c.                                                             

The N. American equivalent, GEFS, remain bullish. Hope for those in the upper reaches of this month's estimation spread lies with them!

Great!

A very topsy turvy year so far. What will July bring? 

http://www.metoffice.gov.uk/hadobs/hadcet/cet_info_mean.html

Met Office Hadley         17.2c        Anomaly        1.7c provisional to 5th

Metcheck                      15.72c      Anomaly        -0.72c 

Netweather                   16.64c      Anomaly        0.15c

Peasedown St John      15.7c      Anomaly        11.15c.

Met Office Hadley         16.9c        Anomaly     1.4c provisional to 6th

Metcheck                      15.61c      Anomaly      -0.85c

Netweather                   16.37c      Anomaly      -0.13c

Peasesdown St John     15.69c      Anomaly      -1.16c. 

Met Office Hadley         17.0c       Anomaly      1.4c provisional to 7th

Metcheck                      15.69c     Anomaly       -0.78c

Netweather                   16.39c     Anomaly       -0.12c

Peasedown St John     15.55c      Anomaly       1.3c.      

Met Office Hadley       17.0c     Anomaly      1.3c provisional to 8th

Metcheck                    15.84c   Anomaly      -0.62c

Netwether                   16.51c  Anomaly        0.02c

Peasedown St John     15.8c    Anomaly     -1.05c.  

Met Office Hadley       17.0c     Anomaly      1.3c provisional to 8th

Metcheck                    15.84c   Anomaly      -0.62c

Netwether                   16.51c  Anomaly        0.02c

Peasedown St John     15.8c    Anomaly     -1.05c.  

 

Still very warm after such a mixed to say the least start.  If we get a heatwave we could easily get above 18c almost without trying. 

2nd half of the GFS 06z of today was the first deterministic run from that model to show the very warm / hot and dry variant of the Scandinavian High regime for the UK.

This has been advertised by longer-range modelling for a while now, but was initially being put forward for the first half of the month, not the 2nd! So it's been put back a fair bit.

Only in the past few days has it finally stopped edging away. Question now is whether runs like the 06z GFS and 00z ECM (based on where it was heading as of day 10) prove to be the start of a journey toward realisation.

So far, the CET has been floating on a cushion of relatively warm nights. It's a similar story where I am - in fact, the daytime highs here have so far averaged over half a degree Celsius below the 1991-2020 baseline, but the nights have been more than one and a half above it!

This, I'll admit, has caught me out a bit - the CET could well finish markedly above my estimate if a very warm 2nd half to the month materialises. I was banking on that, but not quite such balmy nights in the meantime!

Or maybe the 2nd half won't be as warm as anticipated and the two errors will cancel out. Now that would be amusing .