The warning is in place from 4am until 11am on Saturday, July 19 and covers all of London.
It also follows the previous yellow weather warning in place for thunderstorms and rain from 9pm to midnight tonight (July 18).
The Met Office has warned that rain could lead to some “significant surface water flooding during Saturday morning.”
You can see the full weather forecast via the Met Office.
Thunderstorm warnings have been issued for the weekend, but will you catch one?
Find out more in the weekend weather forecast with Alex Deakin pic.twitter.com/Wuaa03Trab— Met Office (@metoffice) July 17, 2025
An amber weather warning has been issued across London
Sharing what to expect, the Met Office shared: “Areas of heavy rain with embedded thunderstorms will move northwards during the early hours of Saturday, with torrential downpours in places.
“Accumulations of 20-40 mm are possible in 1 hour, and where heavy downpours persist then as much as 70-100 mm could accumulate in just a few hours. Significant impacts are possible if this occurs over more urban areas.
“The more widespread heavy rain should clear to the north during Saturday morning, but additional scattered heavy showers and a few thunderstorms could develop during Saturday afternoon and early evening, this risk covered by the much larger Yellow thunderstorm warning.”
How to prepare for thunderstorms and torrential rain
The Met Office has advised: “Keep yourself and others safe; prepare to avoid travelling by road during potentially dangerous road conditions.
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“If you must travel, ensure you watch for possible danger and drive cautiously.
“It is not safe to drive, walk or swim through floodwater, avoid it where possible and if you are affected by fast flowing or deep-water call 999, and wait for help.”
Adding: “Consider checking on vulnerable people that you know including older people, those with underlying conditions and those who live alone; they may need support with food and medical supplies.”
