Thunderstorm warnings are still in place in the UK, parts of which could see as much as three inches of rain on Monday.
The yellow warning began in the early hours of Sunday and will be in place until Tuesday, covering most of England, the east of Wales and the east of Scotland.
On Monday, between 30 and 40mm of rain could fall in an hour across a wide area, and in some places between 60 and 80mm of rain could fall, potentially causing flash flooding, the Met Office said.
Marco Petagna, a senior operational meteorologist, said the thunderstorms were due to low pressure sitting over the UK. He said: “There’s a risk of heavy showers, which could be thundery in places, especially central and eastern parts of the UK.”
He added that flooding, lightning strikes, travel delays and cancellations were possible and there was a slight chance of power cuts.
On Sunday, up to 25mm of rain fell in an hour in parts of Dorset, while temperatures reached 30C in the south-east of England. On Monday, temperatures are set to reach 25C, again in the south-east, while it will feel colder towards the north and west.
Lighter, more scattered showers and sunshine are forecast for Tuesday and Wednesday, but from Thursday more thunderstorms are expected in the south of England.