Britain is set for its hottest day of the year, with temperatures predicted to soar across southern England.
The mercury in London could climb as high as 35C (95F), Greg Dewhurst, from the Met Office, warned.
"It'll be a cloudy start to the day but we'll soon see lots of sunshine across the South East and central parts of England," he said.
Once the cloud disappears, higher temperatures are expected into the afternoon, "particularly the further south and east you go", Mr Dewhurst added.
Friday was the hottest day of the year, according to the Met Office.
The working week ended with the mercury hitting 30C (86F) at around 3.50pm at Achnagart in Scotland on Friday, beating 2019's previous hottest day of 28.8C (84F) on June 2.
A cold front moving in from the west was predicted to bring isolated showers from mid-morning across parts of Scotland and Northern Ireland on Saturday.
Thunderstorms in parts of Scotland and north-east England were also possible.
Overnight the temperature dropped as low as 9C (48F) across eastern England, while western parts of the UK hovered around 18C (64F).
A big change is expected on Sunday on the back of westerly winds from the Atlantic Ocean, with sunny spells predicted across the UK to be interspersed with showers.
Police forces across the country have issued warnings after three people died within 24 hours trying to cool down in rivers and lakes. Advice is not to swim in open water. As temperatures rise the young and old are most at risk from dehydration.