Heat wave in Europe: temperature records in France and the UK, tropical nights and up to 40 degrees in Spain. “An unprecedented event”

French meteorologists say the event had a 1 in 1,000 chance of occurring this time of year, based on climate data from 1979-2025. However, Europe can expect such phenomena to appear more and more often, say the specialists quoted by AFP, Le Monde and The Guardian.

Hundreds of French towns (more than 350) recorded their highest temperatures on record for May, amid an early heatwave affecting other western European states, including the UK and Spain.

Spain in particular could face temperatures of up to 40 degrees Celsius in some regions by the end of the week.

Météo France announced on Monday evening that new monthly highs for May were recorded at 352 weather stations, mainly in western France, with the highest – 37.1 degrees Celsius – being recorded near Hossegor in the Landes department in the country's south-west.

“An unprecedented event with a probability of 1 in 1,000”

“It is an unprecedented event, with a 1 in 1,000 chance of occurring at this time of year, based on climate data from 1979-2025, and virtually impossible in the pre-industrial era,” climatologist Christophe Cassou told Le Monde.

The British weather service Met Office announced in turn that the country's historical record for May was broken with a temperature of 34.8 °C at Kew Gardens in London, writes The Guardian.

New highs are expected to be set in France, Spain and Britain, forecasters said, with temperatures exceeding normal by 12C or 13C in a heatwave described by Météo France as “premature, remarkable and long-lasting” and expected to last for several more days.

Heat dome

France's national meteorological agency said the record temperatures were caused by “a heat dome”, with warm air from Morocco trapped under an area of ​​high pressure.

Europe can expect such events to “occur more frequently and earlier and be more intense,” officials said.

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

“This extension of the heat wave season is entirely characteristic of the effects of climate change,” climate researcher Robert Vautard told AFP. “Eventually, we will see similar heat events in April and October,” he said.

36-37 degrees Celsius in France

A third of metropolitan France's 96 administrative departments were placed under high temperature alert by Tuesday, including eight at the second-highest orange level, which requires residents to “take precautionary measures”.

It was the first time the country's national heatwave warning system was activated in May since it was introduced in 2004.

Météo-France announced on Monday that temperatures could rise locally to almost 36 degrees Celsius in several cities and towns, and up to 37 degrees on Tuesday.

“In the west of the country, temperatures will be several degrees higher than those ever recorded in May,” the agency stated.

Tropical nights and up to 40 degrees Celsius in Spain

The heat wave in Spain – where temperatures in some southern areas reached 38 degrees Celsius at the weekend, 5-10 degrees above normal – is also expected to continue through the week, said Rubén del Campo of the state weather service Aemet.

“The other really notable aspect is that the situation will last at least until the end of the week. In fact, it could be even hotter on Thursday and Friday, with temperatures of at least 34 degrees Celsius in most of the country,” del Campo said.

Maximum temperatures of 36-38 degrees are expected in the Guadiana, Guadalquivir and Ebro valleys between Wednesday and Friday, he added, saying that “in some of these areas, temperatures could reach 40 degrees Celsius”.

Del Campo also said that much of the country can expect so-called “tropical nights”, where the nighttime temperature does not drop below 20 degrees Celsius.

Some parts of the UK could be affected by a heat wave, with temperatures between 26 and 28 degrees Celsius – depending on the area – for three days. In France, for a heatwave to be officially declared, nighttime temperatures must also stay above a certain threshold.