The yellow ‘be aware’ warning covers most of the south-east of England and is for between 4pm and 3am tomorrow morning (Wednesday August 8).
The Met Office says: “Whilst many places will miss the heaviest rain, thunderstorms are likely to affect parts of east and south-east England during Tuesday afternoon and particularly into the evening.
“The last of these storms are expected to clear from East Anglia into the North Sea during the early hours.
“Frequent lightning may occur along with heavy rain (as much as 20-30mm of rain in an hour in a few places), large hail and sudden strong gusts of wind.”
The temperature across the county is set to fall to normal seasonal levels after today.
After hitting 30degC yesterday and today, the rest of the week is due to stay in the low 20s degC.
And there is the possibility of rain during Thursday and Friday.
However, the longer range forecast is for the Hot weather to last until October, predicts the Met Office