Heatwaves: More intense and less predictable

4 March 2026, by Thomas Merten

Photo: Julia Weihe/Unsplash

Sun over Berlin: Heatwaves in Central Europe are occurring more suddenly and more frequently.

Heatwaves in Europe are not only becoming more frequent and intense, but also less predictable. A new study by a team led by Dr. Goratz Beobide-Arsuaga shows that global warming is amplifying the climate system’s internal variability.

“Europe is a real hotspot. The intensity of heatwaves is increasing three to four times faster here than in other regions of the Northern mid-latitude,” says Beobide-Arsuaga. The key factor: soil moisture. When soils oscillate between wet and dry conditions, they can intensify heat extremes. Once dried out, evaporative cooling weakens – and temperatures spike more abruptly.

In Southern Europe, soils are already so dry that further drying has little atmospheric impact. Temperatures remain high, but variability decreases. Central Europe, by contrast, is now experiencing increasingly chaotic summers once typical of the Mediterranean.

Analyzing around 250 climate simulations, the researchers were able to separate the effects of changing internal variability from the long-term warming on European heatwaves for the first time. Their finding: not only are average temperatures rising – the climate system’s flicker is intensifying as well.

For climate adaptation, this means not only planning for gradual warming, but also for sudden record-breaking extremes.

More about the study

The article was published in the CLICCS Quarterly magazine, the research news from the Cluster of Excellence "Climate, Climatic Change, and Society".