41 days of strong heat stress and rivers at a 30-year low: how summer 2026 broke western Europe's records
On 17 days in summer 2026, at least 60% of western Europe was above 30 C. In 2003 that happened on 11 days. In 2025, on 7.
Western Europe, as the Copernicus Climate Change Service (C3S) defines it (11W–15E, 37N–55N), had its warmest summer on record, averaging 21.7 C. That is 2.5 C above the 1991–2020 average, and ahead of 2003.
The records did not stop at air temperature. They reach heat stress, the Rhine and the Danube, and the forests. C3S set it all out in a summer 2026 release and a European Summer Review on 2 October 2026. Summer means June to August, anomalies are against 1991–2020, rankings go back to 1950, and the data may be revised.
How hot was it?
For Europe as a whole, it was the third-warmest summer on record. For western Europe, it was the warmest.
The heat also spilled beyond the season. The release notes record daily temperatures in May and September, and a first major heatwave in western Europe in late May.
Air temperature, though, is not the same as what a body feels.
How did the heat feel?
C3S measures heat stress with the Universal Thermal Climate Index, a feels-like temperature. Its review counts 32 C as strong heat stress and 38 C as very strong.
By the end of summer, 52% of Europe had been exposed to at least very strong heat stress.
Averaged over western Europe, there were 41 days of strong heat stress, a record and five more than in 2003. There were 13 days of very strong heat stress, also a record.
Averages hide the extremes. Some places saw up to a full season of strong heat stress and up to 75 days of very strong heat stress, the review says. Others saw none.
What happened to the rivers?
European rivers had their lowest summer flows in more than thirty years. C3S calls it the most severe low-flow summer since the European Flood Awareness System records began in 1992.
Record or near-record lows were recorded in July and August on the Rhine, Danube, Po, Loire, Rhone and Seine.
The seas were warm too. Sea surface temperatures were at or near record levels across European seas, including much of the Atlantic coast and the western and central Mediterranean.
The release describes prolonged, severe dryness. That was the backdrop to the fire season.
How much burned?
By 2 September, the EU's burned area was almost twice the 2006–2025 average for that date, C3S reports, citing the European Forest Fire Information System. Spain and France saw notable activity.
Wildfire emissions were among the ten highest since 2003, C3S says. The review's emissions chart does not state a 2026 total, and neither do we.
What we do not know
- How many people died. These are climate statistics, not casualty counts. The pages we read give no heat-related death figures, and we do not estimate any.
- How widespread the drought was. The release gives no single drought percentage, so we do not state one.
- Final numbers. C3S data may be revised.
What to remember for the next heatwave
Heat falls hardest on older people, infants, outdoor workers and people with chronic illness, the WHO/Europe heat advice notes. Its basic guidance: stay out of the hottest hours, keep the home cool, drink water regularly, and check on people who live alone.
Sources
Comments (0)
Sign in to join the discussion.
- No comments yet — be the first.