In the United Kingdom, Monday 25 May was recorded as the hottest May day on record, with temperatures reaching 34.8C at the Royal Botanic Gardens in Kew, London, surpassing a record that had stood since 1922 by two full degrees. The following day, the record was broken again, with temperatures rising to 35.1C.
In France, the heatwave shattered May records in more than 300 locations in a single day. The national meteorological service described it as “remarkable both for its early arrival and its duration”. In Spain, Bilbao exceeded 40C, while in Italy cities including Rome, Florence, Bologna and Turin were placed on red alert.
Death toll rises
In France, seven people died from heat‑related causes, including five drownings and two deaths during sporting events – a 53‑year‑old man during a race in Paris and a participant in a Hyrox event in Lyon.
In the United Kingdom, ten drownings were recorded as people attempted to cool off in lakes and rivers.
In Turin, power outages caused by strain on the electricity grid paralysed neighbourhoods and disabled traffic lights. The local utility Iren, which serves 650,000 customers, said the heatwave arrived earlier than expected and that cables were under thermal stress.
London recorded a “tropical night”, when temperatures do not fall below 20C – a phenomenon highly unusual for the country. Only about 5% of homes in Britain have air conditioning, while most buildings were designed to retain heat rather than release it.
Similar conditions prevail across much of western Europe, where infrastructure – from power grids to railways and hospitals – is not designed to cope with prolonged extreme heat in May.
A future already arriving
“We know without any doubt that heatwaves like this have become more likely and more intense because of climate change,” said Peter Thorne, director of the ICARUS climate research centre.
A new report by the World Meteorological Organization and the UK Met Office forecasts that global average temperatures will reach between 1.3 and 1.9 degrees above pre‑industrial levels by 2030. A strong El Niño is expected towards the end of 2026, potentially pushing temperatures to record highs.
Arctic winter temperatures are projected to rise faster than anywhere else, at more than 3.5 times the global average.
More than 62,000 people died in Europe from heat‑related causes in 2024, the hottest year on record.
The UK Climate Change Committee has warned that the country was “built for a climate that no longer exists” – a conclusion that increasingly applies across the continent.
