London Weather: Flood Risk As Amber Storm Warning Issued for the Weekend

July 19, 2025: London Weather – An amber weather warning has been issued by the Met Office as powerful thunderstorms are set to strike London and the South East, raising serious concerns about flash flooding and hazardous conditions across parts of the UK this weekend.

The warning, which is in effect from 4am to 11am on Saturday, marks the first amber alert for London since Storm Henk hit in January 2024. Forecasts suggest between 20mm and 40mm of rain could fall in just one hour, with some areas seeing up to 100mm in a few hours where the downpours persist.

Danger to Life and Disruption Expected

The Met Office warned the extreme weather could result in:

• Danger to life from rapidly rising floodwater
• Damage to buildings due to flooding, lightning, and strong winds
• Transport disruption, with some communities potentially cut off by flooded roads
• Power cuts and delays to trains and road traffic

“There is a risk of fast-flowing or deep floodwater, especially in more urban areas,” a statement read. “Torrential rain and thunderstorms could lead to significant surface water flooding during Saturday morning.”

Broader Impact Across the UK

Alongside the amber warning, yellow thunderstorm alerts cover the north of England, Midlands, and eastern regions from midnight to 9pm on Saturday. A yellow rain warning is also in place from Saturday afternoon through Sunday for parts of eastern Scotland, and again for Cornwall and Devon from Sunday evening into early Monday.

The storms are moving in from France, bringing frequent lightning, heavy rain, and hail in some areas.

Travel Disruption Likely

The AA has urged drivers to take caution, warning that roads may become hazardous quickly. National Rail has also advised passengers to check for delays and allow extra travel time, as speed restrictions may be imposed.

Chief meteorologist Andy Page added:

“This weekend is expected to be busy on the roads as more schools break up for summer. It’s crucial for people to stay up to date with the latest forecast.”

Weekend Weather Outlook

• Saturday: Temperatures to remain cool with heavy cloud cover. Brighter spells in the south could push highs to the mid-20s°C.
• Sunday: Unsettled with continued rain and thunderstorms.
• Next Week: Conditions expected to gradually improve by Wednesday, with fewer showers and more stable weather.

Residents and travellers are advised to monitor updates from the Met Office, local authorities, and transport providers as the situation develops.