Europe’s heatwave now 2°C hotter due to climate change, study finds

A record-breaking heatwave sweeping western Europe would not have reached its current intensity without human-caused climate change, according to a new study by the Netherlands’ meteorological institute KNMI, as reported by Swedish public broadcaster SVT.

Temperatures in the region have shattered May records, with London hitting 35.1°C on Tuesday—the highest ever recorded for the month. In France, over 350 local heat records have fallen, and at least seven deaths have been linked to the extreme conditions.

The KNMI study found that a similar high-pressure system over southern England in the 1800s would have produced temperatures 2°C lower than today’s heatwave. Under a future scenario with 3°C of global warming, the same weather pattern would drive temperatures several degrees higher than the current peak.

Erik Kjellström, professor of climatology at Sweden’s Meteorological and Hydrological Institute (SMHI), confirmed the trend: “At around 1.4°C of global warming today, we already see these intense heatwaves running 2°C hotter than their 19th-century equivalents.”

The data shows heatwaves growing more severe with each passing decade, Kjellström added. “Since greenhouse gas emissions remain extremely high, global temperatures will keep rising—meaning future heatwaves will be even more intense than what we’re experiencing now.”

Health risks are mounting, particularly for vulnerable groups. Researchers at Imperial College London’s Grantham Institute estimate the current heatwave could cause 250 excess deaths in England and Wales alone, aligning with a 2025 study linking extreme heat to increased mortality across 800 European cities. Elderly individuals, those with pre-existing heart conditions, and children—who struggle to regulate body temperature—face the highest risks.

Early-season heatwaves pose an added danger, Kjellström noted, as people have had less time to adapt. “It’s like the first snowfall of winter—it causes far more disruption than later snow because no one is prepared.”