Sweltering temperatures are shattering records across Europe, as the continent battles a deadly heatwave. The heatwave has already claimed dozens of lives in France, where people have drowned while trying to cool down in the punishing heat.
France endured its hottest days in history on Tuesday and Wednesday last week, with western regions reaching highs of between 39°C and 43°C. Wednesday was the United Kingdom’s warmest June day on record, with the mercury climbing to 36.1°C.
Spain, Germany, Austria, the Netherlands, and Switzerland have all broken June temperature records at several sites. The event is not over yet, with forecasts suggesting Poland and Germany will bear the brunt over the weekend.
This historic heatwave is not happening in isolation. It comes days after the global sea surface temperature again reached record levels. Meanwhile, Australia’s weather bureau has declared El Niño active, making a hotter, drier year in Australia, Asia, and the South Pacific much more likely.
So what’s driving this latest heatwave? And why is it so severe? Scientists are losing sleep over the current European heatwave for two main reasons: its timing and severity.
A heatwave occurs when the average temperature is unusually hot for three or more days in a row, compared to past weather data taken from the same location. However, recent research suggests days of intense heat stress are now starting to arrive in June, weeks before the peak of the European summer.
Current evidence shows climate change is making heatwaves more frequent and intense. One study found that without the effect of human-made greenhouse gas emissions, the heatwave that hit southeast England in June 2025 would only happen once every 50 years. However, when the researchers accounted for the temperature increase caused by human-induced climate change, this became at least once every five years.
Researchers point out that the current European heatwave would rarely happen so early in the year, and it also would not be toppling temperature records by such staggering amounts. Tuesday and Wednesday were France’s hottest days since records began in 1947, with an average temperature of 29.9°C across the country.
The heatwave has left many without access to safe cooling methods, with some rivers so warm they could not be used to cool nuclear power plants. In the same week, Spain also set multiple daytime and nighttime records, with one location enduring three consecutive nights of 30°C or above.
At the local scale, heatwaves occur when a high-pressure system settles over a region, trapping heat and pushing it closer to the surface. On a broader scale, climate change from the burning of oil, coal, and gas is reshaping how and when heatwaves form.
Research shows in the five decades between 1950 and 1999, Europe endured five intense heatwaves. Between 2000 and 2021, there were 18 such heatwaves. Add to that the extreme heatwaves of 2022, 2023, and 2025, and this figure rises to more than 20 severe heatwaves in just 25 years.
Heatwaves already pose a critical health risk to people across southern Europe, with communities in southern and western-central Europe most at risk of heat-related illness and death. Children and the elderly are most at risk of heat-related illness, as their bodies are less able to evaporate sweat and regulate their internal temperature.
As the world grapples with the consequences of climate change, the risk of extreme heat — Australia’s deadliest natural hazard — is now a global reality. With global average temperatures at near-record levels for both 2026 and 2027, the risk of extreme heat will only continue to grow in the coming years.
