The Met Office has issued yellow thunderstorm warnings across much of England until 9pm on Saturday, with 15 to 25mm of rain possible in under an hour. Scotland faces a separate yellow warning for rain from 4pm Saturday until midday Sunday.
An amber warning is in effect for London and south-east England from 4am to 11am on Saturday, where heavy rain could cause fast-flowing or deep flood water, posing a danger to life. The amber warning, the first for London since January 2024, predicts 20 to 40mm of rain in an hour, with up to 100mm possible in a few hours.
Thunderstorms moving in from France may lead to significant surface water flooding, particularly in urban areas like London due to impermeable surfaces. Frequent lightning and localised flooding are expected, and motorists have been urged to take care as many schools break for summer holidays.
The Met Office warned that flooding of homes and businesses is likely and could happen quickly, with some communities possibly cut off. Chief meteorologist Andy Page said the situation is evolving and warnings may be changed or added.
Temperatures will stay in the high teens to low 20s Celsius, with brighter spells in the south reaching mid to high 20s. This follows England's hottest June since records began in 1884, with scientists noting that record-breaking extreme weather is now the norm due to climate change.
