Forecasters have confirmed Thursday as the hottest day of 2013 - but warned the balmy summer-like conditions are about to give way to days of chilly temperatures.
Parts of the UK basked in glorious sunshine in the afternoon as the heat soared to 23C (73.4F), beating the previous record set two weeks ago, at 22C (71.6F).
St James's Park in London saw the day's hottest conditions, while parts of southern Lincolnshire, East Anglia, Surrey, Kent and greater London also saw the mercury peak in the low 20s.
But sun-worshippers have been told to make the most of the summer-like conditions while they last, with the UK expected to be faced with temperatures in the low 10s from Friday and into the May bank holiday weekend.
Laura Caldwell, forecaster with MeteoGroup - the weather division of the Press Association - said: "It was warm across the south and the south east of England. There are quite a few 20s and 21s.
"But it will be quite chilly for the next week to 10 days across the country, going into the bank holiday."
She said temperatures will struggle to get above 12C (53.6F) tomorrow, hitting around 8C (46.4F) in parts of Scotland.