The warning is in place between 6pm tonight and 9am tomorrow morning.
It comes as temperatures are set to reach 24 degrees today.
The Met Office said of the warning: “Scattered thunderstorms are expected to affect parts of south-west and southern England this evening, moving north quickly across the UK overnight, clearing Scotland and eastern England by mid-morning on Wednesday.
“Although some places will miss the thunderstorms altogether, where they do occur there is the potential for frequent lightning, hail and gusty winds, as well as sudden downpours in a few places.
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