Spectacular thunderstorms swept across London overnight, causing thousands of lightning strikes and flash flooding.
The storms battered the capital for more than two hours, waking thousands from their sleep as torrential rain filled roads with water.
The lightning is believed to have caused two house fires as London Fire Brigade took hundreds of calls through the night.
The thunderstorm cell erupted overnight catching forecasters by surprise as it generated thousands of lightning strikes.
Londoners shared stunning video clips of the lightning which was observed in all corners of the capital.
What in clartation is going on with this storm in London.
— TacticalBrit (@TheTacticalBrit) June 23, 2026
Crazy thing to capture. #Thunderstorm pic.twitter.com/ka7M7p6q1x
“I’ve not seen anything like this in years in London,” wrote one person on X, who posted videos of flash floods in Ruislip, west London.
Another X user posted in the replies to the message: “The whole road from the Polish War Memorial up to Ruislip was basically under water. Ruislip Manor station also flooded.”
Wow, that was the largest lightning storm I've seen over London in some time. Almost 3,000 strikes recorded in the last two hours alone 🌩️
— James Cosgrove (@MrJamesCosgrove) June 23, 2026
And with first light at 3.55am, London has gone from complete darkness to thunderstorms to full daylight in the space of an hour! pic.twitter.com/SO6nZnjWzM
According to one catastrophe modeler and meteorologist on X, almost 3,000 lightning strikes were recorded over a two hour period.
The rain was described as “biblical” in scale by some on social media.
London Fire Brigade (LFB) confirmed that they took around 400 calls overnight, with firefighters across the city responding to numerous flooding calls.
LFB also attended at least two house fires suspected to have been triggered by the lightning strikes.
Flooded roads were reported in other parts of London including Uxbridge and Raynes Park.
It’s 3.45am in London and it’s been thunderstorming for almost two straight hours.
— Adam Schwarz (@AdamJSchwarz) June 23, 2026
One of the biggest and longest storms I can remember in my almost 35 years in this city. pic.twitter.com/3YQKiAVu57
The heavy rain also caused flooding at Heathrow, with no service between Heathrow Terminals 2&3 and Heathrow Terminal 4 on the Elizabeth line due to flooding at arrivals level.
T4 services were terminating at Hayes and Harlington & West Drayton, causing chaos for many trying to catch early flights.
Quite some lightning from the storm at 4am over South East London pic.twitter.com/cJug5HUBNP
— Gill (@Fleurfox) June 23, 2026
The Met Office said 29,074 lightning strikes were recorded in the UK in the last 24 hours to 9am on Tuesday.
All of these strikes were over England, with the majority – 18,540 – over Somerset.
The Met Office’s lightning map also shows hundreds more strikes across London between around 3am and 6am on Tuesday morning.
It comes as a heatwave builds over London with temperatures expected to nudge 40C in the coming days.
Transport bosses have warned people against all but essential travel amid rare red warnings over extreme heat expected to hit record highs for June.
Temperatures for the latest heatwave are likely to overtake the June record set in Hampshire in 1976 by several degrees and could come close to the UK’s all-time high of 40.3C which was measured in July 2022.
#RaynesPark flooding this morning - avoid Raynes Park Bridge and Lower Downs Rd while the water drains. I have asked @Merton_Council to close the road pic.twitter.com/sIV1y8Cp6R
— Matthew Willis (@MJ_Willis) June 23, 2026
The hot conditions, which have been very rare in the UK until now, will be accompanied by high humidity and very warm nights, which will make it hard for people to recover overnight, the Met Office warned.
A red weather warning for extreme heat covering an area stretching from London to Swansea and Somerset to Birmingham was issued by the Met Office from 9am on Wednesday to 9pm on Thursday.
This storm is something else. I had a job down at Ruislip earlier and this rain and lighting is insane. I’ve not seen anything like this in years in London. I’ve not seen flash flooding this bad in Ruislip in quite a few years #London #Thunderstorm #Lightning #Flooding pic.twitter.com/FE4sJgoLb0
— Joe 🇮🇸🇪🇺 (@JBCOYS99) June 23, 2026
These are reserved for the most severe events, the Met Office said, meaning this heatwave is expected to bring “severe and significant impacts” including widespread health risks for many, not just those who are normally more vulnerable to the heat, and even danger to life.
Scores of schools across England and Wales announced they would close or finish early later this week to protect pupils amid the extreme heat.
