Parts of England could be drenched by a fortnight’s rain in three hours as heavy showers and thunderstorms hit the UK.
Forecasters warned of possible flooding and power cuts as downpours wash way a summer of sunny weather and scorching temperatures.
The Met Office has warned of “intense” rain and has issued a yellow warning for storms in the east of England.
It said homes and businesses could be flooded and buildings could be damaged by lightning strikes or hail.
As much as 40mm (1.5 inches) rain could fall in parts of east and north England during three hours of Monday, said Met Office meteorologist Bonnie Diamond.
“There’s a risk of heavy, thundery downpours, especially later in the afternoon as warmer temperatures in the east help to trigger showers,” she added.
Torrential rain could lead to difficult driving conditions and affect train services, the Met Office said. The yellow warning is in place until 10pm on Monday 20 August.
The Environment Agency has issued 12 flood alerts, meaning people should prepare for possible flooding.
Ms Diamond said the outlook was “mixed bag” around the UK this week, with warm temperatures but sporadic showers.
But the hot weather could make a return in time for the bank holiday weekend at the end of August.
“Towards next weekend it is likely to become generally drier, brighter and more settled, especially for southern parts of the UK where it could become warm or very warm again,” Ms Diamond said.