Exceptionally Strong El Niño Could Drive 451,000 Excess Heat Deaths

An exceptionally strong El Niño developing in the Pacific could cause about 451,000 excess heat-related deaths worldwide between June 2026 and February 2027, according to an estimate from the University of Chicago’s Climate Impact Lab reported by Deutsche Welle. Researchers said the estimate covers only the first nine months allowed by current seasonal forecasts and could rise as the event continues into Northern Hemisphere spring.

Land temperatures are forecast to average about 1.2 degrees Celsius above normal over the coming months. El Niño occurs when Pacific trade winds weaken, reducing the rise of cold water near South America and allowing unusually warm surface water to spread across the central and eastern Pacific. The resulting atmospheric changes can alter weather worldwide, bringing extreme heat and drought to some areas and heavy rainfall and flooding to others.

Federal forecasters told NPR that the event could become the largest in recorded history. Climate scientist Daniel Swain said it is probably record breaking, while The Hill reported that its atmospheric development resembles the powerful 1997 El Niño.

Despite the event’s intensity, NOAA is planning a smaller research campaign than it conducted during the strong 2015-16 El Niño. NPR reported that the agency will deploy several unmanned watercraft, while additional projects depend on congressional funding. NOAA has lost more than 2,000 staff during President Donald Trump’s second term, and his administration is seeking to eliminate the agency’s research office.