Thunderstorms over France are set to move across the country on Saturday July 27, prompting the weather warning, which puts people on standby for possible travel disruption and surface water flooding.
The yellow rain alert - the lowest of three levels, meaning “be aware” - is for London and south-east England, south-west England, the Midlands, East Anglia, and Yorkshire and Humber on Saturday – however, the worst of the rain is expected to affect southern counties.
BBC weather forecaster Ben Rich said torrential downpours were expected to start in the mid-afternoon and by the end of Saturday night would spread into southern and central Scotland.
In its weather warning, the Met Office said: “Thunderstorms and areas of heavy, thundery rain are expected to move north from France during the course of Saturday afternoon and evening.
“The public should be aware of the risk of localised disruption to travel, due to surface water flooding and lightning strikes.”
Despite the rain, temperatures will remain warm for most of the country with a high of 24C (75.2F) expected on Saturday.