Today was set to become the hottest day of the year so far, with temperatures almost matching those in the Caribbean.
The mercury was forecast to rise to 31C (88F), beating yesterday's highest temperature of 30.8C (87F) in Jersey.
A heat warning issued by the Met Office on Friday remained in place, alerting people to the possibility the weather could have a significant effect on health.
Central and north London and the Home Counties were expected to bask in the highest temperatures in Britain, which are forecast to be only 1C (2F) less than the 32C (90F) forecast for the Jamaican capital of Kingston.
Festival-goers packing up their tents as Glastonbury came to a close this morning were blessed with dry ground after the sun turned the mud on the site hard and compact yesterday.
But sunburn was in evidence among the revellers as they headed home, despite repeated warnings over the public announcement system and on screens at Worthy Farm advising people to wear hats and sun-block.
Wimbledon will also see mainly dry weather in the coming days, apart from tomorrow morning when there could be a few showers.
And much of south east England, East Anglia and Lincolnshire were expected to be bathed in sunshine today.
Paul Mott, a forecaster at Meteogroup, the weather division of the Press Association, said: "Yesterday was the hottest day of the year so far. Today will be a little bit hotter so it's probably true to say it will be the hottest day of the year again."
Last year's record temperature is yet to be beaten however, the Met Office said.
On July 8 2010, Gravesend in Kent recorded temperatures of 31.7C, according to a spokeswoman.
And this year's heatwave is set to be over in a flash, with rain forecast to put an end to the rush for ice-creams and suncream.
The south west has already seen wet weather today and more showers and thunderstorms are expected in south east England and East Anglia overnight.
Temperatures in London tomorrow are not forecast to climb higher than 23C, while the west and the north will even see the weather turn chilly.
"Places like Northern Ireland and Scotland will struggle to get up to 16C", Mr Mott added.
"It's a fairly short-lived heatwave, just two days, and for the rest of this week it will remain much cooler."
Temperatures in London and the south east are forecast to drop to 20C later in the week and to 19C elsewhere in the UK.