Yes that little ring was also visible on the Meteociel link, but without a label.
But the 27C minimum temp is even more remarkable, I think!
Incidentally Heathrow was still getting hotter at 6pm, as was Northolt and London City.
Looks like they will just fall short of 30C though.
Edit - Kew Gardens has a highest hourly reading of 29.6C so may have just scraped 30C today.
Originally Posted by: Rob K