Highest temperatures 31 July discussion

[Julian Mayes]

I thought I'd start a thread to collate posts on this subject as the morning temps are quite impressive in places. 

Following the discussion started by Richard in Horsham, the highest 09Z reading at a MO site was 30.4C at Teddington. Heathrow was second at 29.5C.  In this situation I suppose local site factors play a greater part than normal. Will be interesting to see how the heat works northwards with local foehn effects too in Scotland and how much effect the encroaching cloud has from the SW.  

Julian  

[Tim Furdui]

33C at heathrow at 11am (up by 2C in 40min)

29C at london city at 10:50 (up by 2c in 30 min) but here the E'lies means it wont be as hot as west london and the max will be reached later in the day

that been said - the quick rebound of the temp is due to lack of clouds and low humidity of the air thats allowing the heat up so fast 

we could easily reach 35C at heathrow or even 37C if the easterly dont start to kick up there too

[Tim Furdui]

Gone up to 31 at London City in the past 30 min...

[Richard Griffith FRMetS]

Horsham AWS at 11:25z - 32.6°C

Regards

Richard
Horsham AWS

[Tim Furdui]

35C at heathrow at 12:50pm

35C at london city at 12:50pm ( a 2C jump from 33C at 12:20)

Winds picking up now

[Brian Wakem]

Max of 35.6C here so far, now dropped a couple of tenths.  Site record is 35.8C from last July.

-- 

Brian Wakem

Lower Bourne, Farnham, Surrey

http://www.brianwakem.co.uk/weather

Live obs @ 13:35:12 : 35.4C, DP 16.7C, RH 33%, 0.0 mm

[Brian Wakem]

On Friday, 31 July 2020 13:35:28 UTC+1, Brian Wakem wrote:

Max of 35.6C here so far, now dropped a couple of tenths.  Site record is 35.8C from last July.

Temp falling back quite fast now.  'Only' 33.9C.

Smashed my site's diurnal range record:

11.5C -> 35.6C = +24.1C

Previous record was 21.7C  (data since Aug 2013)

 

[Julian Mayes]

Looking at the 12Z readings for the London sites and the 13Z ones just coming in - 34.7 to 34.9C plus Heathrow 35.7C - these are higher than ANY temperature recorded at many of these sites between 1941 and 1970.  Sad that the news presenter on the otherwise excellent LBC at 2pm said 'max temp 35C' in a  totally matter of fact voice, as if it was as 'normal' as 24 or 25C.   Even just a few years ago when Wisley broke the UK JUly record, (35 point something?) it was greeted as an exceptional event. Now everything is judged against the 38.7C at cambridge last year. 

Yes, I've summoned the energy to look up my blue MO 1941-70 averages booklet. Well worth keeping for historical interest.  

Now we have this breeze, the dilemma is whether to open the house windows or keep them closed for another hour or two.  

Julian - still beside the fan.  

[Brian Wakem]

On Friday, 31 July 2020 14:20:27 UTC+1, Julian Mayes wrote:

Now we have this breeze, the dilemma is whether to open the house windows or keep them closed for another hour or two.  

Julian - still beside the fan.  

Keep them closed or you'll just fill your house with 30-35C air.  The wind will just speed up that process! 

[Dave C]

It's days like this that make me appreciate my proper air-con unit fitted to our bedroom last year ;-)

[Len]

To put things in perspective.

Highest 21.5C here at 0930 on the coast in SW Devon.

Then the cloud moved in. Threatened a shower but only had a couple of drops.

Rather humid feel with mistiness from the sea. 83% RH.

Holiday makers are all over the place. This is the new Spain.

LOL

Len

Wembury

[Tudor Hughes]

Maximum temperature here (so far) is 36.0°C, new site record (1983).  Quite a stiff southerly breeze so there should be no problem with an overheated screen.

Tudor Hughes, Warlingham, NE Surrey, 557 ft, 170 m

[Brian Wakem]

On Friday, 31 July 2020 14:46:31 UTC+1, Dave C wrote:

It's days like this that make me appreciate my proper air-con unit fitted to our bedroom last year ;-)

Ditto.  I did some yoga around noon in sub 20C while it was 34C outside!

 

[Tim Furdui]

There was a buzz around how July will go out without a 30C reading in the country

gotta love weather sense of humour 

saved all for the last day and made up for that - 37C in London (whilst no national records broke) - the intensity of the heatwave, the duration/enfolding and the rapid temp increase today - all are very notable 

Paris reached 40C so a few hundreds miles south(er) and could be much hotter 

I also believe most of the mainland UK have had a very warm day today compared to Wed/Thu and tomorrow and early next week

Only regret (but can still be proven wrong) is the lack of thunderstorms (today and this summer in general)

[Graham Easterling]

Here reached 20.5C just as sea mist rolled it, even in the mist it stuck at 20C, dropped to 19.6C around 15:30.

Some mizzle, and a few proper drops recently, but nothing measurable.

Blue sky to the west now, quite a sharp clearance, out on Tresco (scilly) 16:00

Temperature back up to 23C on St. Martin's now.

Off to Sennen this evening, once the families on holiday are getting tucked up in bed. The sun will be glinting off the sea.

Graham

Penzance

[Freddie]

Further west in south Shropshire, it reached 31.1 before the medium cloud rolled in.  Slight rain now (well-spaced large-ish drops) and feeling humid - although the temperature has dropped 3 degrees, the dew point has risen from 11 to 15.

--
Freddie
Alcaston
Shropshire
148m AMSL
http://www.hosiene.co.uk/weather/
Stats for the month so far: https://www.hosiene.co.uk/weather/statistics/latest.xlsx

[Nick Gardner]

On a work trip over to Lyme Regis today, it was heaving. More like Benidorm and it was stifling too. Couldn't see the sand on the beaches for all the umbrellas and burnt bodies. The sea did look tempting but alas, work to do.

[Graham Easterling]

Drifting a bit from Julian's interesting subject, but I don't understand why so many are crammed into so few 'hotspots' with much of the coast so quiet (at least in Cornwall.) It's been commented on in various places. AS an example, St Ives (Porthminster) around noon (Weds) Photo Sara Booker

Meanwhile, my daughter was just the other side of the bay, 3-4 miles away at Godrevy, where it was basically deserted. It is a surfing / windsurfing beach, and there was no usable surf or wind, but even so. There are some great cafes from Hayle towans to Gwithian (the wonderful Sunset Surf) & Godrevy, so it's not exactly remote.

It's a mystery, my theory is that people who like to get out and about in the more open places have been more cautious about coming away to an area like Cornwall in peak season. The one's that have come are more the settle on the beach, get sunburnt, go to a theme park, visit the amusement arcade, sod social distancing type. With the amusement arcades mainly shut, the indoor attractions which have opened on much reduced capacity, they all head for the St. Ives gift shops and the nearest beach to them. St Ives is simply awful in summer, after the October half time I dare to return.

Graham

Penzance - sun's back out now.

[Julian Mayes]

Here in north Surrey - the widespread Ac is now accompanied by towering cu over London area - but not towering much, alas.  

Julian  

[Dave C]

Maxed at 36.0C here late afternoon. Thought there might be some radiation effects but ties up well with others and lower than Heathrow.

[Len]

Yes Graham,

but are there pubs near these deserted beaches?

And are there beach surf schools to try a bit of surfing?

It's all about having it on a plate.

Len

Wembury

[Keith (Southend)]

31st July 2020

32.5°C maximum for me at Eatwood/Southend-on-Sea.

This is my 3rd hottest day on record in dataset back to 1960.

1st 35°C 4th August 1990

2nd 34°C 25th July 2019

4th 32.2°C 26th June 1976

Shoeburyness (03693) 30.2°C

Southend Airport METAR 34°C

Keith (Southend)

[Graham Easterling]

Yes,

Theres a surf school at Gwithian, 800-1000 yards from where that photos taken. All run from the Sunset Surf Cafe Bar https://www.sunset-surf.com/ . Even nearer is the Godrevy Beach Cafe, 400 yards away or so

https://www.facebook.com/Godrevy-Cafe-141060335960379/photos/?ref=page_internal . 800 yards away, just next to the entrance to the Godrevy car park, the Rock Pool

https://www.facebook.com/TheRockpoolBar/

It's a very odd year, even allowing for Covid.  I was just speculating the reason why the people who have come down this year seem to be the ones who just visit the hotspots, browsing shops for Piskies, NT tea towels, and cuddly seals. If they went to Godrevy they could see the real thing, several dozen on occasion (I have photographic proof!) One of my photos after swimming with several seals.

Lovely at Sennen this evening, the best wave for a while, for those with 2 fully operational legs! About 19:30

A significant proportion of the surfers locals after work. You can tell, they change in the car park, it stops getting sand everywhere. No lifeguard after 5pm.

Graham

Penzance (not at all hot!)

.  

[Richard Griffith FRMetS]

Now the data is in, yesterday's maximum air temperature of 34.8°C was the 3rd highest for my location since records commenced in 1983. 1st - 2006 36.2°C, 2nd - 2019 34.8°C 3rd - 2020 34.8°C

Ci and Ac, Cu did develop and spread from the SW during the afternoon. Cold Front went through during the early hours, cloud cover associated with the front kept temperatures above 15°C until 04:30z.

Attached is a comparison for 25th July last year and yesterday.

[Julian Mayes]

Hi Richard, 

3rd highest not equal second? I assume there's a hidden decimal place.   The striking thing about your graph is something I was pondering yesterday evening while sitting outside cooling down in the breeze - how early the max temp was. On many exceptionally hot days we've been 'saved' (as if it isn't hot enough) by either a breeze or developing cloud in the afternoon - as was the case in August 2003 IIRC. Doesn't this mean that the day will come, possibly not too far ahead when this does not occur and we reach 40C?      We may not have much warning either -  since about 2016 haven't we had several single hot days with no build-up of a heatwave beforehand?  Yesterday was another example of how intense heat simply arrives suddenly. 

While I'm writing random thoughts, this was another hot day where the exceptional heat was concentrated in the eastern two-thirds of England. This is where there's an upwards trend in very hot days - have a look at the map in Figure 1 in this recent paper...

 https://www.nature.com/articles/s41467-020-16834-0

- further evidence for an increasing north-west / south-east climatic gradient perhaps?  

Julian   

[Tudor Hughes]

    The earliness of the maximum was very noticeable here and was due to synoptic-scale changes.  The wind tended to veer a little and decrease and the short sea-track of the late morning was replaced by a more marine path.  This continued for the rest of the day until "normal" westerlies had taken over but there seemed to be no discontinuity between the hot continental air and the routine warmish Atlantic air, no doubt to everyone's great disappointment.

     I found the Nature article rather hard going.  It was numerically rigorous and no doubt proved its point but there was no mention of the possible synoptic changes that will bring this about.  Others have noted that British heatwaves are becoming short, sharp and intense and this can only be due to changing synoptic patterns.

      It seems to me that meteorology is becoming a wholly numerical exercise.  I would like to think there's still a bit of art left in it.

Tudor Hughes, Warlingham, NE Surrey, 557 ft, 170 m.

[Tudor Hughes]

On squinting more carefully at the max thermometer I have to say I cannot claim 36.0°C but it will have to be 35.9°C, putting it equal to the temperature recorded on 10 Aug 03.  Record equalled but not beaten.

Tudor Hughes.