Copernicus: record 52% of Europe faced "very strong" heat stress in summer 2026

The EU's Copernicus climate monitor said on Friday 2 October that a record 52% of Europe was exposed to intense, or "very strong", heat stress during summer 2026. 1 Copernicus defines "very strong" heat stress as temperatures that feel hotter than 38C. Around 80% of the continent had "strong" heat stress, meaning feels-like temperatures above 32C, which occurred on a record 41 days by the end of the season. 1 It was Europe's third-warmest summer on record and the hottest for western Europe, where surface air temperatures from June to August were 2.5C above the recent decadal average. 2 1

Several countries reported all-time national temperature highs, and four of Europe's top 10 heatwaves occurred this summer, according to Samantha Burgess of the European Centre for Medium-Range Weather Forecasts (ECMWF), which operates Copernicus. August 2003 still ranks as the most severe on record. 1 In western Europe, at least 60% of the area exceeded 30C on 17 days, against 11 days in 2003 and seven in 2025. Western Europe also had a record 13 days of "very strong" heat stress. 2 The heat began unusually early, with a powerful heatwave in late May, and continued into September. Recurring heatwaves killed tens of thousands of people, according to both outlets, and the Guardian adds that they ruined harvests and shut power plants. 2 1

Dry conditions brought the lowest river flows in more than 30 years (since records began in 1992), according to Copernicus, which disrupted freight transport and strained irrigation, nuclear reactor cooling and hydropower. Burgess said drought affected almost half of Europe by the end of August. 1 2 European sea surface temperatures also set records this summer, the report found. 2 The Guardian also reported that fire weather was the worst recorded, according to European Forest Fire Information System data published on Wednesday. About 680,000 hectares had burned by the end of September, the third-worst total behind 2025 (about a million hectares) and 2022 (768,000). Smoke released 30% more fine particulate matter than the two-decade average. 2

Burgess said the heat stood out for its geographical extent as well as its intensity, and that multiple records appeared together across the climate system. The Guardian quoted her as saying such events underline the importance of building resilience to interconnected climate risks. 1 2 Both outlets attribute the heat to climate change. The Guardian specifically blames fossil fuel pollution and notes that an El Niño of unprecedented strength is raising global temperatures, although its effects in Europe are mostly indirect, such as higher food prices and inflation. It also quotes Xavier Rodó of the Spanish research institute ISGlobal, who was not involved in the report, and reports calls from doctors and scientists to stop burning fossil fuels, shade buildings, green cities and install air conditioning in hospitals, schools and care homes. 2 1