With heat records seemingly getting broken for fun these days, often by some margin, the question has to be asked..can 40c be achieved in the UK, if so, when ?

The 2003 record of 38.5c could have been bettered had it not been for high cloud that drifted across at 4pm.

NAVGEM modelled 42c last year showing it is not out of the realms of possibility.

2017 has been an incredibly warm start to the year with widespread 17c/18's in February, 22c in March and no doubt a (surprise) 25c (77f) somewhere on Sunday as models continue to underplay T2M's in the run up to T+0.

Ground conditions are dry, high pressure is dominant...40c is becoming a real possibility IMO.

What is everybody else's thoughts ? 

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I agree, Steve. With the 'extremes' becoming more extreme I think it is inevitable at some point we'll see synoptics line up for a surge of heat to break through the 40C barrier. Like you say we might have already broken it had it not been for high cloud 

40C plus a thundery breakdown 

 

Interesting. I seem to remember seeing a headline on the front page of the Metro newspaper the day after the all-time record of 38C was recorded in August 2002 which said something like "the record won't last. The hottest we've had it since was at the very start of July 2016 when 37C was reached, the all-time hottest temperature in July. The irony of that was that the weather that month then went downhill fast and IIRC it actually ended up returning a slightly below average CET, which incredible given how hot it had began.

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I think it's definitely a matter of when not if to breach the 40c barrier. I would not be at all surprised if somewhere in the country already has but just not at an official station. I also believe that the likelihood is that in the Medieval Warm Period this country has possibly already seen it in the past. Certainly if the synoptics set up just right at the right time I think above 40C is very possible in the near future. All it will need is latent heat and dryness and a long lasting HP cell just to our East and I'm certain it will be breached. And having experienced 40c and high humidity in Australia I think it would be unbearable. I love extremes but 40c + is a scary thought.

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FWIW, I reckon that 40C would almost certainly have been recorded in August 2003 had that record-breaking spell gone on for even a few days longer than it did. The temperatures during that spell seemed to be on the rise continuously until the peak of the heat was reached on the 10th. Only after that did the temps start to come down slightly.

Wouldn't want that sort of heat and humidity again though tbh, and yes we had it here too, although the temps were never quite as high as down south. Trying to sleep at night was pure hell!

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Hear, hear. Likewise if that plume in early July 2015 had lasted a few more days I think we would have done it also. We broke the 2006 record then, and that was only a 48-hour Spanish plume.

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I am going to stick my neck out and say we will hit 40C this year. The fact that we have had very dry conditions in the south for much of the past 9 months (see my post in the March CET thread) will help if these conditions persist into the summer. 

Actually within the list of years in my March CET post very few went on to see a warm and dry summer. The exception of course was 1976. July 1934 was also very warm with a CET above 18C although the maximum temperature was only 33.3C.

Kew Gardens or Gravesend always records the hottest temp in the UK - usually 9/10 it's either one of those which is the hot spot.

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Yeah I could see it and I'll also have a wager that if we did get a 40*c you'll be sitting in that plunge pool with the webcam running 

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Yep..naked. 

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Globally temperatures seem to rising at a worrying rate. Perhaps Climate change is accelerating and the consequences will suddenly hit us and governments are totally unprepared  and some are  in denial

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A scoot through the CET series dating back to 1659 shows us that 7 of the 12 months have recorded monthly CET records in the last 23 years..what does that tell us ? 

courtesy of https://en.wikipedia.org/wiki/Central_England_temperature

 

January	7.5 °C (45.5 °F)	1916
February	7.9 °C (46.2 °F)	1779
March	9.2 °C (48.6 °F)	1957
April	11.8 °C (53.2 °F)	2011
May	15.1 °C (59.2 °F)	1833
June	18.2 °C (64.8 °F)	1846
July	19.7 °C (67.5 °F)	2006
August	19.2 °C (66.6 °F)	1995
September	16.8 °C (62.2 °F)	2006
October	13.3 °C (55.9 °F)	2001
November	10.1 °C (50.2 °F)	1994
December	9.7 °C (49.5 °F)	2015

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A bit off topic, but when you see that the warmest December on record is warmer than the warmest March on record by some margin, it kind of makes you wonder what kind of March we could potentially see. This March just gone broke the daily CET record for the warmest March day at 15.1C, so I actually wonder if we could see a 10.0C or maybe even a 10.5C March at some point in the future?

That February record looks like it might go soon as well.

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Indeed. I like to refer to the stats below which show a very strong warming trend when you look at long term means. Since 1960 the rolling 30 year mean has been increasing at about 0.25C per decade. The last 20 years though are 0.30C warmer than the 1981-2010 mean. So the warming has clearly been accelerating, notwithstanding a short spell of very cold weather earlier this decade.

JAN	FEB	MAR	APR	MAY	JUN	JUL	AUG	SEP	OCT	NOV	DEC
1997-2016	4.6	5.0	6.7	8.9	12.0	14.7	16.6	16.5	14.5	11.1	7.5	5.1	10.27
1981-2010	4.4	4.4	6.6	8.5	11.7	14.5	16.7	16.4	14.0	10.7	7.1	4.6	9.97
1971-2000	4.2	4.2	6.3	8.1	11.3	14.1	16.5	16.2	13.7	10.4	6.9	5.1	9.75
1961-1990	3.8	3.8	5.7	7.9	11.2	14.2	16.1	15.8	13.6	10.6	6.6	4.7	9.48

In the 28 years from 1989 to 2016 there were 19 years where the CET mean was above 10C (i.e. above the 1981-2010 mean)

In the 28 years from 1961 to 1988 there were only 3 years where the CET mean was above 10C (the highest being 10.08C in 1976.

That tells you all you need to know.

Is this a temporary blip in temperatures? Absolutely not. Between 1659 and 1988 (a period of 330 years) there were only 29 years where the CET exceeded 10C. In the following 28 years the CET exceeded 10C 19 times.

So it is most certainly a question of when not if we see 40C in the UK. I think it will be very soon indeed, quite possibly this year. 

40C is definitely possible in theory. Just need a synoptic jackpot (and preferably not a one-day wonder), favourable (lack of) cloud cover etc.

The background of dry, warm/mild weather of recent months certainly wouldn't harm our chances of seeing 40C this year, but wouldn't like to bet on it... for all we know, summer could still turn out to be cool and wet!

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If we were to see an enduring build up of heat, as in 2003, over the continent, but earlier, then get the right conditions say in mid July (bearing in mind that by 10th August the sun's strength is only equivalent to about the 1st May) then surely 40+ is on. 38.5C is actually not that far off.

1st July 2015 was also plagued by a cloudy interruption, yet the July record still went. I reckon, somewhere in the 12th-22nd July range, with 850s above 20, a light E/SE drift and unbroken sunshine, and favourable antecedent conditions including dry ground, SSTs not too low, surely it's manageable.

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I should see it happening sooner than late and we had many miss chances in July 2015 when whole of France was 38-43C all month while here was 18-21C from 2nd week to rest of July.  I prefer a slow gradual rise to 40C then gradual drop not not quickie type hot spells like 1st July 2015.  

You have to consider night time temps need to reach 23-25C to support 40C during the day.  Back in 2003 was 17C overnight to 38.6C but 39-40C on the road at 3pm so there a chance that my area had reached 40C including my old Brannon max and min thermometer read 41C 106F at 5pm.  I used the wired thermometer that record temps every sec that reached 38.6C at 5pm for 1 second.

You need a good thermometer that record every second otherwise you miss out vital stats.  The useless WS2500 I had recorded every 30 secs to 1 minute and that time in July 2006 was 36.5C so maybe I would had got 37C in between 30 seconds.

It was not 38-43°C across the whole of France for the whole month of July 2015!

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Most long time temperature records tend to peak around first 10 days of August.  Being an island, thermal lag trumps insolation, up to this point.  Having said that, I do not disagree that the time period you specify is "game on".

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As we probably reached 40C in 1808 and temperature averages are considerably warmer now than then the only surprise to me is that it hasn't happened yet and suffice to say I think it will almost certainly happen at some point soon.

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In a nutshell, we are overdue a 1976-style Summer - mind you, that one was more noted for the prolonged dryness rather than heat records. But I guess we are at this time of the year where hopes and expectations are high for the summer when it usually ends up being a crushing let down, a bit like come Autumn we start hoping we go onto a 1947-style winter.  

But I think I'm missing the point of this thread. Yes, I do think a 40 C will be breached before 2020 but in the form of a short-lived blink-and-you'd-miss-it event, and then go onto becoming a near-yearly event most summers by 2040. I'd be in my 70's by then, more older and grumpier than I am.  

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Cue an IDJ cartoon about a grumpy IDJ complaining about my Ark when the 2040 deluge arrives. 😂😂😂

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Already ahead of you . . .

Me in 2040 . . .

 

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😂😂😂😂

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I also agree that we will breach 40C within the next few years. I would love to see it happen this summer but I'm not going to hold my breath. I'd also like to see our first month with a CET of 20C or higher, and a month where an official station such as the London Weather Centre, Gravesend or Cambridge records an average monthly maximum of 30C.

We will have to wait and see