Britons are enjoying the hottest early May Bank Holiday Monday ever recorded, the Met Office said.
Forecasters said the mercury hit 25.1C (77.1F) in Gosport, on the south coast, on Monday morning - beating the previous record of 23.6C in 1999.
Monday's high temperatures are predicted to soar to a sweltering 29C (84.2F) in parts of the South East, as people round off their three-day weekend.
This would make it the hottest overall early May bank holiday weekend, smashing the previous record in 1995 when temperatures peaked on the Saturday at 28.6C (83.4F)
Met Office forecaster Greg Dewhurst said: "We have smashed the warmest Bank Holiday Monday for early May, but for the whole bank holiday weekend itself we have got to be over 28C (82.4F).
"The highest temperatures of the day will be around 3-4pm so we will probably know more then."
Asked if he thought the overall weekend record would be broken, he said: "It's going to be close I think. All indications show the temperature's going to get very close so yes, a good chance."
The early May bank holiday was introduced in 1978 and the temperature over the long weekend has never topped the 28C (82.4F) mark.
The South East and central southern England are most likely to feel the most heat, while the majority of the UK will see temperatures between 23C (73.4F) and 27C (80.6F).
The maximum average temperatures for May are 13C (55.4F) in the North and 16C (42.8F) in the South.
This weekend's hot conditions have been created by a mix of low pressure, light winds and consistent sunshine.
But not everyone will see blue skies - it will be cloudier across Northern Ireland and Scotland, the Met Office said.
And low cloud, mist and sea fog is affecting the northern coast of Devon and Cornwall.
The weather is set to become mixed as the month progresses and the May 19 wedding of Prince Harry and Meghan Markle draws near.
Looking at the long-range forecast, which is not as accurate as the shorter range forecast, Met Office forecaster Charlie Powell said: "It looks like we should be prepared for some pretty changeable weather throughout the second half of May.
"We're still going to see some dry days, but there's still going to be some wet days mixed in as well."
Referring to the day of the eagerly anticipated wedding, Mr Powell added: "We've got this idea that there could be some warmer spells, most likely across the south and east of England, so at least that bodes well for wedding locations and things like that."
He said temperatures will generally be above normal, but this will depend on whether it is a sunny day or a sunny, wetter day.
"So it doesn't look like it's going to carry on in a similar kind of vein to high pressure in charge, sunshine, light winds, high temperatures, that we have now.
"Neither does it look like it's going to be a complete washout, horrible end to the month of May.
"But I think we can expect things to be not as warm as they are now, but also not as dry as they are now," he said.
Mr Powell added: "Fingers crossed it all kind of ties in with one of the drier days."