Is that a forecast going tits-up? (Sorry, couldn't resist!)

FWIW here near the coast exposed to the NE wind there's some low-level cloud rolling in from the sea... looks for all the world like the cloud you get when mist has just lifted!

Really useful resource; thanks. Two things:

the 35.4 on 26 June was not from Mayflower Park (that reached 34.9 that day). It was North Heath (W Sussex), East Dereham (Norfolk).

http://www.torro.org.uk/hightempsyear.php

Also, although the old-quoted 38.1 from Tonbridge, Kent on 22 July 1868 has been discounted, might there have been other stations that at least reached 35? It would be masked of course by the 1911 figure from the same date in the Torro record. That might be worth a look.

Im sat in a park in Stansted a beautiful small town by the way and it certainly feels every inch 30c . Very oppressive.

I may be wrong but I don’t think Stevenson screens were in use back then so none of the records will be directly comparable, but I think the rule of thumb is to knock 1.5 to 2C off those old Glaisher stand temps? So surely still above 35C and most likely around 36. 

There are some other figures from that spell here: https://www.netweather.tv/forum/topic/90217-1005f-at-tonbridge-22nd-july-1868-the-last-great-8-summer/

Gosport fleetland was 30.2C at 1pm - currently over 31C at privately owned stations in Gosport as we approach 2pm. Here in north portsmouth its 32C .

went for a walk and its pleasant in the shade with the cooling breeze. Perhaps the cold boundary layer has yet to burn off

Thanks for the reply Rob.

The cuttings include a >35 at Stratfield Turgis which is included in the Torro records for Sep 1895, so as long as they didn't upgrade their station in that 27 year period, it must stand as a 35+ day.

12z sounding's in from Herstmonceux:

http://weather.uwyo.edu/cgi-bin/sounding?region=europe&TYPE=GIF%3ASKEWT&YEAR=2020&MONTH=08&FROM=0912&TO=0912&STNM=03882

It's interesting - there was still an inversion, but no longer at the surface; instead it became "cut off" as low level-heating commenced. It wasn't  enough to override the modification, but during the afternoon that inversion should shrink away.

Northolt seems to be shooting up. I checked a short while ago and was 29C. Now 31C.

30C hear now next to City Aiport.

St James's park 31.5c. Can we get 35c?

Temperaturs have surged in the last 30 minutes. We may well do.

Gosport Fleetlands is slightly ahead with 31.8 at 2pm. Will need a big surge to get anywhere near the 35. Quite a bit more cloud bubbled up here in the last half hour, temp 28.7.

And there has been a big surge with Heathrow putting on almost three degrees to 32.9C. Herstmonceux 32.8. 

Heathrow 32.9c

Interesting that that should coincide with the forecast removal of the inversion, or rather the mixing-out of the North Sea layer...

Yes indeed, it’s certainly been noticeable. It felt pretty fresh until about 1pm but the temp has rocketed since then. Interesting to know what is responsible.

Temp has risen from 22.9 at noon to 29.1 at 3pm! 

3pm temperature at Gosport fleetland was 33.2C 

Gosport Fleetlands 33.2c

Waiting for the downwind effect here. For me, it's strange to see 29.1°C reported by Bournemouth Airport for 3 pm yet still expect a max there in the 30s °C - and perhaps more than just slightly. Such is the unusual nature of the 'weather flow' today!

Presumably, there should be a similar 'surge' in temperature, though maybe not quite as dramatic given not as much new surface heat input from the sun. Yesterday, the BA temp rose from 31°C at 4 pm to peak at 32.9°C somewhere between 5 & 6 pm BST, one of the most extraordinary things I've seen for that weather station.

That, though, was with the aid of clearing skies after quite a bit of cloud. So I'm not sure the jump can be as much today from whatever is observed at 4 pm... but we'll see!

I'm a little suspicious of the figures coming out of Heathrow. I'm just a few miles down the road and my back garden thermometer is just below 30c. Perhaps their barometer needs recalibrating or moving to a slightly more shady site.

Thanks for these additional points. 

The readings from 22 July 1868 are interesting. I found a book on the Met Office Archives on London weather dated from 1968. This has interesting facts on the past. There were several stations that recorded 95F+ in July 1868. Greenwich being the main one but that site has long since been discounted due to non-standard exposure. Isleworth also comes up but I have never seen this quoted in lists of extremes so again I assume it has been discounted. 

The most reliable station quoted in the book is Epsom. This station has the recognised maximum for 22 July 1911. The book states that Epsom recorded 97F on both 22 July 1868 and 22 July 1911. No Celsius figures or decimals in those days. 

So I am going to add to my list Epsom at 36.0C for 22 July 1868, consistent with the 1911 reading.