I did mean to post this chart yesterday.
It shows a count of consecutive days above the threshold heatwave temperature - as laid down by the powers that be at the Met Office.
I had to use a calculated fixed distance from central London to know which threshold to use rather than the regional map the Met Office decreed should be used. I used 15, 20 and 120 nautical miles which roughly equates to the threshold bands in the map.
As you can see heatwave conditions exist at 17 sites across the UK as of 18 UTC yesterday evening which is likely to increase substantially today.

This zoomed up version is for Julian and others in the London area.
