This thread is for all comments, discussion and analysis of temperatures in the UK during August, 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 back yard. 

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

Historic CET summary for August

1971-2000 16.2C (30 years) 

1981-2010 16.5C (30 years) 

2000-2019 16.1C (last 20 years)

The warmest August in recent times was last year with 17.1C. Other than that we had not exceeded 17.0C since 2004. In 2003 we saw 18.3C which is the highest since the record of 19.2C in 1995. The coolest recent August was 2014 with 14.9C.

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

Direct link to larger version of the chart

Current model output 

GFS 850s Looking rather warm after a cooler first few days of the month.

GFS 850's https://www.wetterzentrale.de/de/show_diagrams.php?geoid=49069&model=gfs&var=2&run=00&lid=ENS&bw=

GFS T2m https://www.wetterzentrale.de/de/show_diagrams.php?geoid=49069&model=gfs&var=5&run=0&lid=ENS&bw=

ECM also looking potentially very warm from next Friday

ECM ENS T2m 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/forecast-temp-aso-v1.pdf

Looks fairly close to average in terms of probabilities

Hmm... just into the new month, post-deadline, and the models produce some of the hottest runs I've ever witnessed.

Though the hot signal has been inescapable for a number of days now, such prolonged heat as the GFS 12z shows would be surprising. It takes a rough CET estimate from a mere 16.1°C as of 4th to a whopping 19.5°C as of 9th and then on to a peak of 20.5°C as of 16th.

I went above average for Aug but not by a huge amount! Reason being, quite strong signals pointing toward cool zonal weather by the final third... in other words, more or less the opposite situation to the July signals!

I'm not too worried at this stage, of course. It's the first day of the month! Also, the GFS 06z was only hot for the CET region 7th-9th and gave a CET estimate to 16th of 18.8°C, after which average conditions would bring it down to the low 17s.

 

Very interested to see how much the warm signals in the mid-range has influenced the spread of CET estimates for this month. I've a lot of repairing to do after July's major mishap... probably too much, but I may as well continue for the heck of it!

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Though the hot signal has been inescapable for a number of days now, such prolonged heat as the GFS 12z shows would be surprising. It takes a rough CET estimate from a mere 16.1°C as of 4th to a whopping 19.5°C as of 9th and then on to a peak of 20.5°C as of 16th.

I'd happily sacrifice my CET prediction to witness the shear intensity and longevity of the heat being modelled across the NWP tonight (especially ECM/GEM). 

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I'd happily sacrifice my CET prediction to witness the shear intensity and longevity of the heat being modelled across the NWP tonight (especially ECM/GEM). 

Indeed. I went in the mid-17s and if this evening's models are right I could be horribly wrong.

I'd love to finally see a proper hot, summery August! One is well overdue now.

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Indeed. I went in the mid-17s and if this evening's models are right I could be horribly wrong.

I'd love to finally see a proper hot, summery August! One is well overdue now.

Yes, I did the same and I agree with you and Steve.  But isn’t it usually the case that when it’s prediction time at month end, the output fools us?  At mid 17c, I’d happily have gone too low if we get a good August.  It could all change of course, as it often does!  

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A possible temperature of 35c Good week has already ruined my prediction.🤔🤔🤔😕😷

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Met Office Hadley         17.3c       Anomaly      1.1 Provisional to 1st.

Metcheck                      16.77c     Anomaly      0.55c

Netweather                   18.58c     Anomaly      2.39c

Peasedown St John     15.22c      Anomaly      -1.16c. 

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Here is the August tracker. We could be close to or even above 19C by the middle of the month if the latest output is to be believed. The next couple of days are quite cool though. 

Main thing stopping us going even higher is that the really hot weather doesn't make it to the north of the CET area for the most part.

Chart1

Chart2

 

Just checked what CET figure I sent in for August. Oh dear.

 

 

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Here are the predictions for August

TABLE

Met Office Hadley         16.7c        Anomaly       0.5c Provisional to 2nd.

Metcheck                      16.59c      Anomaly       -0.37c

Netweather                   17.6c       Anomaly        1.41c

Peasedown St John      15.12c     Anomaly       -1.26c.      

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I predicted the hottest August since 2004 with just 17.2c which is all it would take.
Looks like I'll be right about the first part at least.
But like many others on the thread , I feel an August of 1995/97/2003 style heat and sun will more than compensate for a slide down the table

Met Office Hadley          16.0c.        Anomaly       -0.2c

Metcheck                       15.93c       Anomaly       -0.29c

Netweather                    16.88c       Anomaly       0.69c

Peasedown St John      14.65c       Anomaly       -1.73c.

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Met Office Hadley          16.0c.        Anomaly       -0.2c

Metcheck                       15.93c       Anomaly       -0.29c

Netweather                    16.88c       Anomaly       0.69c

Peasedown St John      14.65c       Anomaly       -1.73c.

Notable that the CET can be cooler than average while here in London we’ve had 28, 25 and 24C maxes (and another 24 today) and mins in the mid teens. Shows the west-focused nature of the CET. 

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Met Office Hadley           15.6c     Anomaly        -0.6c. provisional to 4th.

Metcheck                        16.30c   Anomaly       0.08c

Netweather                     16.58c   Anomaly       0.39c

Peasedown St John       15.68c    Anomaly      -0.7c.

      

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Incredible stats. Central England is clearly another country. Here in London the max and mins since start of the month have been:

TMx: 27, 25, 24, 25
TMn: 16, 12, 14, 11

Notwithstanding a couple of cool nights that’s still mean max 2C above average and mean min 0.75C below, so well above average overall.

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Not sure how well the 3 stations are positioned for the upcoming hot spell- but at least the nights look to be on the warm side, so I wonder what GW makes of the CET track over the next week.

If we had a week of 19 that would take the mean above 17, but we'll need a lot more than that to repair the seasonal CET after a rotten July and a slow out of the blocks August.

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To anyone with a 16s to low 17s prediction getting hot under the collar at the sight of a heatwave in the forecasts - I wouldn't worry too much at this stage.

While runs such as the latest GFS suggest that the CET may climb to the 19s °C by 11th, there is a general signal for something fresher to take hold by the 3rd week of the month.

The GFS 06z shows this and drops my rough CET estimate down to the low 18s as of 20th. Thereafter, average conditions would take it down to the mid-17s for the month's end.

Admittedly, it could well be a bit hotter than that GFS run shows and for all we know could take a bit longer to cool off. On the other hand, there is a La Nina base state in place, which means tropical forcing will be increasingly inclined (as the month progresses) to return to an arrangement that will encourage a mobile westerly to northwesterly flow regime across the UK.

If it wasn't for a monumental push of the MJO (which features a region of enhanced tropical thunderstorms propagating eastward) against this La Nina base state which is currently taking place, we'd be looking at a westerly-dominated month with a CET near or a little below average.

 

Within all that is the reasoning behind my mid-16s CET prediction. Let's see how I fare when toward the lower end of the spread...! 

 

p.s. It's looking markedly hotter down my way; my local mean could well be in the 19s °C as of Saturday and 20s by Monday! Looking at 3-5 days of maximums in the 30s °C... impressive for these parts.

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Incredible stats. Central England is clearly another country. Here in London the max and mins since start of the month have been:

TMx: 27, 25, 24, 25
TMn: 16, 12, 14, 11

Notwithstanding a couple of cool nights that’s still mean max 2C above average and mean min 0.75C below, so well above average overall.

I'm actually slightly confused what locations are currently used for the Hadley CET. I thought it was Rothamsted, Pershore and Stonyhurst but the Met Office website also mentions Malvern and Squires Gate (is that the one up in Blackpool?). 

I live just a few miles from Rothamsted and I can vouch for the fact that it is significantly cooler than even St Albans. It is a semi-rural location on the outskirts of Harpenden. I regularly cycle past the location on my way to work and in the winter, the drop in temperature as I approach that location is often stark (especially in clear, calm mornings). Daytime maxima are typically 1C lower than here too. Stonyhurst appears to be surrounded by industrial freezer units as it is often the coolest location in that area, frequently cooler than other locations at a lower altitude. Pershore also tends to have very cool night minima. During July it had 4 nights with minima below 6C! 

Furthermore, in a westerly or north westerly regime, the western location bias comes into play too. Even more so if Squires Gate is being used.

So, I'm not really sure how representative it is of 'Central England' but it is a relatively consistent data set that can be used for data comparisons. 

 

 

 

 

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Unless they are different to suspected, I think the sheer 'rurality' of several of the CET stations makes the CET highly sensitive to clear nights with light winds. That was an unusually frequent feature of last month. So often, I was willing an area of high pressure to position itself a few hundred miles further east for the overnight period!

Then again, I'm often doing that anyway between April and October .

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