An Imperial College and London School of Hygiene and Tropical Medicine study estimates that heat killed 6,824 people in Spain this summer. Researchers attribute 5,227 deaths to climate change.
In Madrid, researchers estimate that climate change contributed to 967 of the 1,067 heat-related deaths recorded this summer. Barcelona’s estimated toll was 1,842, with 1,587 deaths attributed to warming linked to fossil fuel burning. The figures come from a study by Imperial College and the London School of Hygiene and Tropical Medicine, published on 22 October, which assessed summer heat mortality in 854 urban areas across 30 European countries.
The researchers estimate that 6,824 people died from heat in Spain between June and August 2026. They attribute 5,227 of those deaths, around 77%, to climate change. The study covered 90 Spanish urban areas, and its figures are epidemiological estimates based on modeled heat exposure, not a count of individually verified deaths.
Across the study area, researchers estimated more than 50,000 excess heat deaths, with about 32,000, or 65%, attributed to human-caused climate change. The analysis compares mortality under observed 2026 temperatures with a cooler counterfactual climate, approximately 1.4°C cooler than today’s global climate. It estimates the additional mortality associated with human-induced warming rather than identifying individual climate-related deaths through death certificates.
Barcelona ranks second among European cities for deaths attributed to climate change, behind Milan. Madrid is sixth in the European city list. The estimated climate-related share is higher in Madrid: 91%, compared with 88% in Barcelona.
Other Spanish cities also appear in the study. In Valencia, 262 of 355 estimated heat deaths were attributed to climate change, or 74%. The corresponding estimates are 77 of 109 in Seville and 71 of 98 in Granada. Zaragoza recorded an estimated 264 heat deaths, of which 169 were attributed to climate change.
The national total for heat deaths is below the roughly 13,000 recorded in 2003. Yet Spain’s summer of 2026 was the hottest since records began in 1961: the average temperature reached 24.5 degrees, and 61 days fell under a heatwave. AEMET, Spain’s State Meteorological Agency, reported that the 24.5°C mean for peninsular Spain was 0.3°C above the previous record, set in 2025.
The scientists built their estimates by comparing summer temperatures in today’s climate, which has warmed by about 1.4 degrees globally, with temperatures in a cooler pre-industrial climate. Earlier reporting on weather-related damage in Spain examined insured agricultural losses in a report on DANA damage.
Spain ranks third in Europe for estimated heat deaths overall, behind France and Italy. For deaths attributed to climate change, it ranks second, behind Italy and ahead of France.
