Fascinating. I'm punting with somewhere just SW of the Humber. However, this second 850Hpa heat spike late afternoon tomorrow (26c) across the far SE has the potential for Kent to claim the early evening prize.

24.8°C here. A bit up on this time yesterday.

The Cirrus naughtius and Altocumulus obnoxious seems to be declining though the Hazus maximus is visible giving the sky a paler blue than I’m used to in recent weeks. Whatever, it seems to have minimal impact on the temps which outside the office on a north facing wall is 27C. Hot in my book though I’m not expecting 40C in this part of the South. Flat calm too.

28.4c here and Doncaster showing 28c. 

Cazaux 34.8C at 10am BST. certainly on pace for early 40s at the lowest

St James's park 29.3c at 10am 

Wisley 30.2 and Writtle 29.8 look to be leading the way

Yes today is comparable to 2003 and 2019. Tmrw is uncharted territory. 

£0C now here, light breeze which is better than last month June gale force winds at 31C.  This allow the temps to go higher if winds are not too strong.

25.0c here at 10:30hrs....impressive to say the least. 

2003 was 30.6C at 10:30am 2019 was the same and today bang on 30C. As you say tomorrow could be in a league of its own.

30.0C reached at 10.44am here.

Looking back at the 2020 heat thread it was only 30.3C at midday.

It's a shame the 2019 heat watch thread doesn't seem to have survived on TWO.

Southend 30c at 10 takes it over
Feels very hot now in these parts
Approximately rising 3c a hour
On target
https://cm2weather.co.uk/gauges
A bit of a solar problem but mighty hot  none the less

A mere 24 degrees here, some high level cloud around.

Just hit 32 here, but it took 15 minutes to get that last 0.1C. At least the stupidly fast rises have stopped here for now.

This must be turning into a good year for the vines is it not Tim?