Weather patterns: Climate change fueling Europe's fiery heat wave

The Problem of Timing

In Europe, the peak summer heat typically arrives in mid- to late July, about a month after the summer solstice. However, recent data suggests days of intense heat stress are now arriving much earlier, in June. Since 1950, only one other major heatwave has arrived earlier than the current one, which is unfolding weeks before the traditional peak of the European summer.

Current evidence shows climate change is making these heatwaves more frequent and intense. A study on the heatwave that hit southeast England in June 2025 found that without human-made greenhouse gas emissions, such an event would occur only once every 50 years. Accounting for the global temperature increase of 1.3°C caused by human-induced climate change, the probability increased to at least once every five years. In a world without climate change, this extreme heatwave would rarely happen so early in the year, let alone topple records by such staggering margins.

France averaged 29.9°C across the country during its hottest days, with 41 local weather stations recording figures above 43°C. The country also slept through its warmest night ever, with a national average minimum of 21.6°C. This overnight heat was intense enough to warm rivers to the point where they could no longer be safely used to cool nuclear power plants. Simultaneously, parts of Spain surpassed 45°C, with one location enduring three consecutive nights of 30°C or above.