The Climate Impact Lab at the University of Chicago projects that extreme heat linked to El Niño could cause 451000 additional deaths between June 2026 and February 2027. Spain could see around 480 additional deaths between September and February, with Madrid and Andalusia expected to face the heaviest impact. Catalonia is also at high risk, as these are among the country's most populated regions.
The projected toll would put this year's phenomenon in a category of its own. Scientists say El Niño in 2026 could become the strongest ever recorded. The report describes its temperatures as astonishing, reaching Godzilla-level intensity, and frames the event as a warning of what climate change could bring within 20 years. BBC and the UK Met Office report that the developing event has exceeded previous temperature benchmarks in the central-eastern equatorial Pacific, including the earlier peak recorded in 2015.
The Climate Impact Lab projects 44% more extremely hot days than in typical years, helping explain the sharp rise in the expected heat-related death toll.
For Spain, the immediate risk is concentrated in the coming months, rather than spread evenly across the winter. Emily Grover-Kopec of the Climate Impact Lab says most of the country's additional heat deaths are expected in the current month. The estimate covers deaths attributable to the phenomenon itself; it excludes the separate effects of droughts and floods, as well as wildfires. The broader assessment identifies heat waves as the basic source of projected mortality and warns that El Niño can disrupt food supplies and water availability.
Spain already faces repeated climate-related risks. An earlier health report showed how quickly a separate medical risk can become concentrated in Spanish hospitals. The El Niño estimate points to a nationwide danger driven by temperature.
Michael Greenstone, co-founder of the Climate Impact Lab, says researchers can now estimate how heat affects crops and its worst possible human consequence. He says the projected 451000 deaths represent individual lives, not an abstract statistic. The report identifies the regions expected to suffer the greatest losses so emergency measures can reach places where they could save the most people. About 239000 of the projected additional heat deaths are expected within the nearest six-month period. The wider assessment covers June 2026 through February 2027 and aims to identify regions where emergency measures could have the greatest effect. Reuters and the Associated Press separately reported the basic findings, including that the figure counts additional heat deaths; it does not represent total deaths from all causes.
El Niño begins with warming in the equatorial Pacific, then disrupts weather patterns around the world. The Pacific has reportedly recorded a water temperature increase of 3.05°C, exceeding the 3.02°C measured at the end of November 2015, the highest figure recorded in the previous 150 years. The Met Office says the new peak is so higher than the previous modern benchmark, rather than a simple repeat of the 2015 event.
The burden is expected to fall most heavily on poorer regions. Nigeria, Indonesia, Sudan and India are among the countries listed as potentially facing the largest death tolls. The Democratic Republic of the Congo, Niger and Chad are also on the list. The United States appears among the 20 most affected nations, with a projection of 3500 additional heat deaths.
The Climate Impact Lab says mortality must become a central part of El Niño preparation, alongside efforts to protect food security. Tamma Carleton, a co-author of the report, says emergency responses and targeted planning could save many lives now. She also warns that temporary emergency action cannot become the permanent answer to temperatures that may be normal in 20 years.
The figures are forecasts; they are not a final death count. Authorities have a map of the regions where intervention could matter most and a short period in which to use it. Spain's projected losses are concentrated in Madrid and Andalusia, with Catalonia also facing a heavy toll. The response should focus on those populations first, instead of treating the threat as a distant global statistic. El Niño is a seasonal weather event that tests whether emergency planning can keep pace with heat the report says may soon become ordinary.
