Researchers at the University of Chicago's Climate Impact Lab projected on Wednesday, September 23, 2026, that the current "super" El Niño could cause approximately 451,000 excess heat-related deaths worldwide between June 2026 and February 2027. The report, titled "451,000 at Risk," excludes deaths from droughts, wildfires, floods and disease outbreaks associated with the same event, meaning researchers say the true toll could run higher.
The report was released before formal peer review, though it applies peer-reviewed methodology. A Climate Impact Lab spokesperson said the findings "couldn't wait for the peer review process to play out," calling later publication "too late to act for this El Niño cycle." Global land temperatures are projected to run about 1.2°C above normal, producing 44% more extremely hot days than a typical year. The report describes the pattern as a "postcard from the future," delivering conditions climate change would otherwise reach two decades from now.
Where deaths are concentrated
Researchers project Nigeria (31,400), Indonesia (19,300) and Sudan (17,600) as facing the largest national tolls. The Sahel region's aggregate estimate reaches roughly 66,800, and Southeast Asian nations including the Philippines, Vietnam, Thailand and Cambodia total about 19,400. India's projection stands at 15,800, with nearly half concentrated in December through February, its normally cooler season. The methodology drew on temperature-mortality data from 24,378 regions worldwide, compared against average months from 1996 to 2025.
Separately, the underlying El Niño itself set a record. Daily sea surface temperatures in the central-eastern Pacific reached 3.05°C above average on September 19, according to reporting cited by BBC Weather, exceeding the 3.02°C peak recorded during the 2015 El Niño, and arriving roughly two months earlier in the calendar year. The World Meteorological Organization says there is almost 100% likelihood the pattern persists through February 2027, with peak intensity expected around November 2026.
Observers are reading: the specific emergency measures researchers say could still prevent tens of thousands of the projected deaths.
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A projection, not a fixed toll
Researchers frame the 451,000 figure as a baseline, not a certainty, tied to early warnings, cooling centers and expanded healthcare access. The estimate follows France's confirmed roughly 1,000 heat deaths in June and cascading fire emergencies that followed.
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