Britain recorded its hottest day of the year so far on Thursday, the country's national weather service said, with provisional data showing a high of 32.6 degrees Celsius in south east England.
This year's previous high was 32.2C, which was reached twice in June, the Met Office said, helping make that month the hottest June on record in Britain.
Met Office Chief Meteorologist Steven Ramsdale said temperatures were "well above average for the time of year" due to high pressure to the south east of the country.
"Heatwave conditions have already been met for much of England and Wales, with parts of Scotland and Northern Ireland also likely to continue to see some unseasonably high temperatures," he added.
The Met Office said last week that Britain had experienced its eighth warmest summer since 1884.