The night sky over southern England erupted in a spectacular chain reaction of lightning on Monday, with the Met Office recording 29,000 strikes in a matter of hours – a display one Londoner described as “biblical”.
The storms, which swept from the south west into the south east, brought torrential rain that flash-flooded roads, submerged tube stations and triggered two house fires in London that the fire brigade believes were caused by lightning. London Fire Brigade said it responded to 400 calls overnight, while in Bristol a house was set ablaze earlier in the evening.
“29,000 lightning strikes hit southern England overnight, sparking house fires and flash floods as the UK braces for record 40C heat.”
The Met Office confirmed 29,074 lightning strikes were recorded in the UK in the 24 hours to 9am on Tuesday, all over England, with the majority – 18,540 – over Somerset. The overnight drama in London saw almost 3,000 lightning strikes over a two-hour period, according to a catastrophe modeller on X.
At Heathrow, flooding at arrivals level shut down Elizabeth line services between Terminals 2&3 and Terminal 4, with trains terminating at Hayes and Harlington and West Drayton, causing chaos for early-morning travellers.
The violent storms were the product of a classic recipe: intense heat and humidity. The Met Office explained that Monday’s temperatures soaring into the high 20s and low 30s transferred energy into the atmosphere, which was then triggered by an atmospheric disturbance higher up. “It’s because it’s a high volume of rainfall falling incredibly quickly,” said Met Office spokesman Grahame Madge, describing flash flooding that overwhelms drainage systems.
Now the heat that fuelled the storms is set to intensify further. A red extreme heat warning – only the second ever issued by the Met Office – comes into force on Wednesday and Thursday across parts of the South of England, the Midlands and Wales, with temperatures forecast to reach 39C or even 40C. That would shatter the June record set in the infamous 1976 heatwave.
The hot and humid conditions will continue to create “tropical nights” where overnight temperatures in urban areas stay above 20C, giving people little chance to cool down. Dr Agostinho Sousa, head of extreme events and health protection at the UK Health Security Agency, warned: “A red heat health alert indicates a risk to life for even the healthy population.”
Across the Channel, a heatdome has settled over western Europe. France, Spain and Portugal are all under extreme heat warnings, with the UK government issuing travel advice urging Britons to check forecasts and take precautions. Tragically, two children aged two and four were found dead in a family car in Carpentras in southern France, in an incident believed to be linked to the weather.
As the UK braces for the peak of the heatwave on Wednesday and Thursday, the Met Office expects some relief by Friday when temperatures drop to the high 20s Celsius. But with humidity still high, the question remains: when the heat pulls back, will the violent storms return?