Europe's June heatwave shatters records, rivals 2003 as climate change loads the dice

A heat dome over Europe

A stalled high-pressure system trapped hot air from North Africa over the Iberian Peninsula in late June, creating a heat dome that spread north and east. Temperatures hit 40°C in Germany, the Czech Republic and Poland, while one French town recorded 44°C. The UK Met Office noted the combination of sustained heat, exceptional humidity and very warm nights.

We got many temperature records during this heatwave and the most impressive thing, we were still in June. So this is a big difference.

Comparisons to the 2003 disaster

The episode drew immediate parallels to the August 2003 heatwave that caused tens of thousands of excess deaths. France's weather service said the 14-day June event was more intense than 2003, though two days shorter. Meteo France recorded 114 instances of temperatures above 40°C between 17 and 29 June, compared to 87 during August 2003.

Climate change makes extremes more likely

World Weather Attribution called it the most severe heatwave ever recorded based on a three-day average of peak temperatures. The network said such an event would have been virtually impossible without human-induced climate change, and a similar June 2003 heatwave would have been about 2°C cooler.

Human-induced climate change has made events like this more likely and more intense.

Rising death toll and future risks

The heat caused transport disruptions and an estimated 1,000 excess deaths in France alone. Last summer's heatwave led to 2,300 climate-related deaths across 12 European countries, according to WWA. Dr Hans Kluge of WHO Europe warned that heat-related mortality has risen by an average of 52 per million people annually since the 1990s.

Heat-related mortality is likely to remain a feature of Europe's warming climate.

What comes next

Europe has warmed at roughly twice the global average since the 1980s, Copernicus data shows. At current emission rates, an event of this magnitude is expected every couple of decades, and today's extremes are a preview of an ordinary summer by mid-century. Another heatwave is already building.