More than 20 towns in France record highest ever May temperatures

More than 20 towns in France have recorded their highest-ever May temperatures and the UK set a national heat record amid an extreme early-summer heat event that could see the mercury climb to 40C in parts of Spain by the end of the week.

The UK’s Met Office said the country’s all-time temperature record for May was broken on Monday when a temperature of 33.5C was recorded at Heathrow near London, with highs of up to 35C expected later on Monday and on Tuesday.

Hundreds of further May records are likely to be set in France, Spain and the UK, Météo France said, with a “premature, remarkable and long” heat episode expected to last several more days and temperatures exceeding norms by 12 or 13 degrees.

Météo France, the national weather agency, said the record temperatures were caused by a heat dome, with hot air from Morocco trapped under an area of high pressure, adding Europe could expect such events “more and more often, more and more intense, and earlier and earlier”.

Models have already estimated that, with the effects of climate breakdown, June heatwaves are now about 10 times more likely in Europe than they were in the preindustrial era, and the same trajectory is becoming visible for May.

“This extension of the heatwave season is entirely characteristic of the effects of climate change,” Robert Vautard, a climate researcher, told Agence France-Presse. “Eventually, we will be seeing similar heat events in April and October.”

Eighteen French départements have been placed on high-temperature alert for Monday, authorities said, the first time the country’s national heat warning system has been activated during May since it was introduced in 2004.

Météo France said in a bulletin on Monday that temperatures could climb locally to 36C. “Towns in the west of the country are likely to see temperatures several degrees higher than ever recorded in May,” it said.

Among France’s larger cities, Paris hit 32.6C on Sunday and is expected to reach 33C on Monday, while Bordeaux sweltered in 34.2C. The south-western town of Brive-la-Gaillarde registered 35.3C, nearly two degrees hotter than its previous May record.

A man died during a 10km running race in the Paris suburb of Maisons-Alfort on Sunday, civil defence services said, reportedly after suffering a heart attack, while 10 more runners had to be taken to hospital in critical condition after the race.

Previous May highs were exceeded locally on Sunday all along France’s Atlantic coast at weather stations including St-Nazaire, where 31.8C was recorded on Sunday, Noirmoutier (31.3C) and Brest in Brittany (29C), the national weather agency said.