Thundery showers are set to bring the recent heat wave to an end this afternoon.
Despite a sweltering start to the day and temperatures reaching around 27C across south London and Surrey, forecasters are warning of disruption as the day progresses.
A Met Office forecaster said: "This afternoon isolated heavy and thundery showers will eventually develop, with the showers becoming slow moving, leading to a low risk of localised flooding."
And the mixed weather looks set to continue overnight.
"Isolated heavy, and thundery showers at first, gradually dying away overnight to leave long clear periods and patchy mist," the forecaster warned.
"Meanwhile areas of fog may affecting some coasts at times. Minimum temperature 13C."
Another dry start on Tuesday would be replaced by cloud throughout the day, he said.
"Again the day will start dry, with large amounts of sunshine," the forecaster added.
"Then cloud will build, bringing a chance of isolated heavy and thundery showers during the afternoon and evening."
However, temperatures will remain high, around 23C.