A yellow weather warning has been issued for thunderstorms in parts of England and Wales.
The Met Office has said the scattered storms across areas including Wales, the West Country, the Midlands and London could lead to disruption and some flooding.
More than half a month’s worth of rain could hit some areas during the warning period, from midday on Monday until 10pm.
On Sunday afternoon showers started to hit the Reading and Bristol areas, before the further thunderstorms will develop on Monday, Met Office meteorologist Becky Mitchell said.
It comes after much of the rest of the country had seen a hot and sunny weekend.
Ms Mitchell said: “It’s another hot and humid day across the southern areas and that’s going to trigger thundery showers.
“On Monday between 20mm and 30mm of rain could fall in an hour and between 40mm and 50mm in the space of one to two hours. There’s the possibility of flooding and disruption, that’s just going to depend on those heavy showers lingering.”
Hail and localised power cuts are also a possibility within the warning area, she said.
Northern Ireland could see some potentially heavy rain on Sunday night and the north west of England and southern Scotland could see scattered showers on Monday afternoon, but the same level of impact as the warning zone is not expected.
From Tuesday onwards, the weather is forecast to turn more settled, with highs of low to mid 20s, which could mean Northern Ireland and Scotland see their hottest days of the year so far, Ms Mitchell said.
On Sunday, a 42-year-old man’s body was recovered on Sunday following searches for a swimmer who went missing in Loch Ard on Saturday, Police Scotland said.
A search was launched after the swimmer was reported missing from the loch, which is in the Trossachs National Park, at 9pm on Saturday.
Police Scotland’s diving and marine unit were involved, along with a mountain rescue team and an air support unit. There are not thought to be any suspicious circumstances surrounding the death.
