Thunder and heavy showers are forecast for parts of UK as the good weather comes to a brief pause.
Showers are expected to sweep across south-east England, the Midlands and South Wales on Sunday evening, the Met Office said.
On Monday, northern and eastern parts of England will bear the brunt of the worst weather, with heavy showers and thunder forecast during the day.
Met Office meteorologist Becky Mitchell said: “Those showers could be quite heavy and intense, and thundery in some areas.
“However other parts of the country will see a relatively nice day.”
Ms Mitchell said it will be dry with sunny spells elsewhere in England, with temperatures expected to hover around the high teens and low 20s.
Dry and sunny conditions will return on Tuesday for most areas, although cloudy skies are forecast across Scotland and Northern Ireland.
Temperatures on Tuesday are expected to peak at 25C around London.
The South East is forecast to remain dry on Wednesday with the mercury reaching highs of 25C again, while other areas could see some cloud and rain.
A similar picture is expected on Thursday, with cloud and rain forming in the west, ahead of a largely dry weekend.