A powerful El Niño event developing in 2026 is projected to cause more than 450,000 additional heat-related deaths worldwide over the next six months, according to a recent study by the University of Chicago’s Climate Impact Lab. The analysis, published this week, projects increased mortality linked directly to elevated temperatures associated with the weather phenomenon through February 2027.

The report estimates that global land temperatures could rise by about 1.2 degrees Celsius (2.1 degrees Fahrenheit) above average, resulting in extremely hot days occurring 44 percent more frequently than in a typical year. The impacts are expected to be particularly severe in developing regions and across Africa’s Sahel zone, where vulnerable populations face higher exposure and limited resources for adapting to heat stress.

Within the Sahel, approximately 66,800 additional deaths are forecast, with Nigeria facing the greatest toll at an estimated 31,400 excess fatalities. Other countries with significant projected increases include Indonesia, with 19,300, and Sudan at 17,600. Southeast Asian nations—specifically the Philippines, Vietnam, Thailand, and Cambodia—are collectively expected to see nearly 19,400 extra deaths. India is projected to experience around 15,800 heat-related fatalities, while Brazil could see approximately 13,300.

Michael Greenstone, co-founder of the Climate Impact Lab and co-author of the study, emphasized that elevated heat is most dangerous in regions where baseline temperatures are already high and income levels are low. “If you’re already in a hot place, the extra couple of degrees are going to be much more dangerous,” Greenstone said, noting that wealthier countries tend to mitigate risk through greater access to cooling technologies, stable water supplies, and healthcare.

Experts caution that the health risks associated with this El Niño may persist beyond its official duration, potentially extending into the summer of 2027. The current El Niño began forming in June and is expected to be among the strongest on record, with the United Nations’ World Meteorological Organization indicating a 100 percent probability it will last through at least February 2027.

Abhiyant Tiwari, a heat specialist with NRDC India, highlighted that while many countries have formal heat action plans in place, effective protection of vulnerable populations remains a challenge. “The real measure of our preparedness is not how many heat warnings we issue, but how effectively we protect people and reduce preventable deaths,” he said, calling for improved funding and implementation of heat mitigation strategies.

Researchers also point to climate change as intensifying El Niño’s effects, describing the current event as "supercharged" compared to historical patterns. As these risks mount, the study underscores the urgent need for global efforts to address heat-related health impacts, particularly in regions with limited adaptive capacity.