The UK yesterday basked in the hottest day of the year so far, but beachgoers are being warned to stay away from part of the south coast after thousands flocking there caused a major incident to be declared.
The mercury rose to a scorching 33.3C at Heathrow Airport in west London yesterday, beating Wednesday's high of 32.6C at the same location.
Scotland also had its highest temperature so far this year, with the thermometer reaching 30C in Prestwick.
The heatwave is set to break with the arrival of thunderstorms bringing lightning strikes and downpours. The mercury hit 24C in Northern Ireland, but a yellow weather warning was in place for thunderstorms last night, lasting until 9am today.
Yesterday, Bournemouth, Christchurch and Poole council said it was left with no choice but to declare a major incident after services were "completely overstretched" as huge numbers of visitors defied advice to stay away during the hot weather.
Condemning the "irresponsible" behaviour of crowds who gridlocked roads, dumped rubbish, abused refuse collectors and parked illegally, the council said extra police patrols have been brought in.
Chief medical officer for England, Professor Chris Whitty, urged people to follow social distancing rules in the hot weather or risk causing a spike in coronavirus.
He wrote on Twitter: "Covid-19 has gone down due to the efforts of everyone but is still in general circulation. If we do not follow social distancing guidance then cases will rise again.
"Naturally people will want to enjoy the sun but we need to do so in a way that is safe for all."
Health Secretary Matt Hancock also tweeted: "We all want to be outside and enjoying the glorious sunshine but if you are heading out please do it safely and stick to social distancing rules."
Bournemouth East MP Tobias Ellwood echoed calls from Dorset Police and the council for people to stay away.