Western Scotland and Northern Ireland are expected to start the day with showers, with stronger rain developing around lunchtime.
"It will be nowhere near as hot as yesterday, Some places will see showers with bursts of 10 to 15 millimetres in an hour, but it won't be especially heavy," said Met Office meteorologist Alex Burkill.
• READ MORE: Map shows incredible number of lightning strikes over Edinburgh yesterdaySeveral European countries have reported record temperatures this week, including France which hit an all-time heat record of 44.3C (111F) on Friday, while in Scotland, Friday's reading of 30C (86F) at Achnagart in Scotland surpassed the previous record of 28.9C for this year, set on 2 June.
Supermarket giants Tesco said sales of barbecue food had soared over the past few days.
However, on Saturday evening the Met Office issued a severe weather warning for thunderstorms in Edinburgh, East Lothian and the Scottish Borders, with thousands of lightning strikes between the hours of 18:00 and 23:59.