The Met Office has issued a thunderstorm warning running throughout Thursday that is set to affect millions – and could see some hit with a week’s rainfall in an hour.
It warns that there is a yellow warning for storms and heavy showers covering almost all of the south of England.
Forecasters say there are risks of sudden flooding, ‘difficult driving conditions’ and a risk of delays to public transport services.
They have also warned of a ‘slight chance’ of power cuts in the affected areas, and a chance of flash floods.
The storm warning covers dozens of areas across three regions of England:
- Yellow warning: East of England, from 10am-9pm
- Yellow warning: London & South-East England, from 10am-9pm
- Yellow warning: South-West England, from 10am-9pm
In a statement, the Met Office said as much as 25-35mm (1-1.4 inches) of rain could fall within an hour – equivalent to a week’s average rainfall for some.
Some areas could see as 60mm (around two inches) in two hours – more than some parts of the UK would typically see across the entirety of June.

A yellow thunderstorm warning has been issued for large swathes of the south of England

The warning runs from 10am until 9pm Thursday (pictured: tourists sheltering under umbrellas earlier this month in London)
‘Thunderstorms and heavy showers are expected to develop during Thursday morning and through the afternoon,’ it said.
‘These could produce torrential downpours in a few places with as much as 25-35mm of rain falling within an hour and perhaps 60mm within 2 hours.
‘Frequent lightning and hail will be additional hazards.
‘Storms will tend to become more confined to the south and east of the warning area later in the afternoon before dying out during the evening.’
Britain has endured a wildly changeable summer – from heatwave conditions in a record-breaking June through to a more miserable July.
An amber warning for thunderstorms was issued earlier this month covering parts of the south, with milder yellow warnings covering almost all of Great Britain.
Wet and windy weather looks to be the norm going into August, with ‘unseasonably deep’ low pressure set to affect the UK.
The Met Office said ‘broadly changeable’ weather is then expected moving towards mid-August, with some drier and more settled conditions to come in the second half of the month.

A map shows how large amounts of rainfall, indicated in yellow and red, are set to spread across parts of England