The South East and eastern England are set to be hit by thunderstorms and heavy rain tomorrow as the Met Office issued a yellow warning.
Forecasters said 50mm of rain could fall in some areas over several hours, and driving conditions may be affected by spray, standing water and even hail.
This could mean longer journey times for motorists and bus passengers, and there may also be delays to train services.
Power cuts, flooding and lightning strikes are possible, and some buildings could be damaged.
The warning is in place from midnight tonight to 3pm on Thursday.
On its website, the Met Office wrote: “Outbreaks of heavy, thundery rain are likely to develop and move across east and southeast England from the early hours of Thursday.
“10-20mm of rain is likely over quite a large area but with some embedded thunderstorms some sites are likely to see 30 to 40mm in two to three hours and perhaps 50mm or more over six hours.”
It added: “Lightning will be an additional hazard. The area of rain is expected to ease from the southwest before clearing into the North Sea during Thursday afternoon.”
Forecasters have also warned there needs to be a period of above average rainfall to ease the drought.
So far this month, the UK as a whole has had only 46% of the average total rainfall for August, the Met Office said.
Much of the country has seen even drier conditions – with only 35% of the total expected rainfall for the month so far in England, 34% in Wales and 39% in Northern Ireland.
And in southern England, there has been just 29% of the month’s average from 1991 to 2020.