People in Spain seek shelter from the sun.

The UK Met Office says that during the current unusually hot weather across the country, temperatures in some areas could reach 35 degrees Celsius, the highest May temperature ever recorded.

On May 25th, a temperature of 33.5 degrees Celsius was recorded at Heathrow Airport in London, breaking the previous record of 32.8 degrees Celsius set in May 1922 and repeated in May 1944. The UK health safety agency issued an amber health alert.

In France, the national meteorological agency also warned of a prolonged, unusually early heatwave, with temperatures at least 12 degrees Celsius higher than the average for the same time of year.

The city of Nantes in western Belgium experienced temperatures of 35 degrees Celsius on May 25th, nearly exceeding the record high of 30 degrees Celsius set in May 2017. The agency issued a yellow alert for 18 provinces in western Belgium and the Paris metropolitan area.

On the same day, in Belgium, the Royal Uccle Observatory in Brussels recorded temperatures exceeding 30 degrees Celsius at several points. This is the highest temperature ever recorded in May since meteorological data began to be systematically compiled.

Meanwhile, Spain and Portugal are predicted to experience the most extreme heat. Some areas in Portugal could see temperatures close to 40 degrees Celsius, while southern Spain could reach 38 degrees Celsius. On May 25th, Spain issued yellow heat alerts for several northern regions.

According to meteorological experts, the cause of this unusual heatwave is believed to be a "heat dome" phenomenon, where a mass of hot air from North Africa is trapped under a high-pressure system covering Western Europe, causing temperatures to soar to levels typically only seen during the peak of summer. This is a clear manifestation of global climate change.