A weather warning for heavy rain and lightning has been issued by the Met Office for tomorrow (Friday June 2).
The main area for the warning (between 1pm and 11pm) is London and further north but it does extend down to Crawley and Horsham.
A Met Office statement says: “There is the risk of torrential downpours on Friday afternoon and evening.
“Whilst most places will miss the worst, it could lead to localised surface water flooding and difficult driving conditions.
“Frequent lightning and perhaps hail could be additional hazards.
The Chief Forecaster’s assessment is: “Very warm, humid air coming up from France brings the threat of thunderstorms which have the potential to give 25-30mm of rain in an hour.”