The Met has issued a yellow thunderstorm warning across Bedfordshire today and tomorrow as heavy rains continue.
The weather warning covers most of England and all of Wales, with torrential rain bringing a possibility of severe flooding in some areas.
It follows baking hot weather last week, with last Thursday setting the UK's hottest July day on record, as temperatures reached 38.1C (100.6F) in Cambridge.
In England, only Kent, East Anglia and parts of the Northeast are free of weather warnings today. Warnings are also in place across Wales, and in the Dumfries and the Highlands regions of Scotland.