The average rainfall for the UK in July is 78.1mm, meaning around a fortnight’s worth of rain was expected in the one-hour period.
Sheena Engineer, Flood Duty Manager at the Environment Agency said: “Slow-moving thundery showers could lead to localised surface water flooding, mainly across parts of western England on Tuesday, with the risk extending north and east into Wednesday.”
The Met Office put out a yellow rain warning for the north of England all day on Wednesday, with a yellow storm warning for Wednesday afternoon and evening in Scotland.
More normal conditions are forecast to return from Thursday.
Last week, the UK set a new all-time temperature record of 38.7C (101.66F) which was recorded in Cambridge.