Super-strong El Niño could lead to 450K deaths. Map shows the states hit hardest

(NEXSTAR) – Climate scientists are warning that this year’s El Niño could be one unlike we’ve ever seen before. Expected to be super-strong, the climate phenomenon is likely to fuel drought in some areas, flooding in others, and as many as 451,000 weather-related deaths.

In a report released Wednesday, the University of Chicago’s Climate Impact Lab estimates that 451,000 deaths may be attributed to El Niño-driven extreme heat.

“This is such a large number that it can be numbing, but it is made up of parents and children, grandparents and neighbors, people going to work, caring for families, and living their lives,” said Michael Greenstone, Climate Impact Lab co-founder and professor.

Most of those heat deaths are projected to be in the Southern Hemisphere, where El Niño’s peak strength lines up with the summer season. (In the Northern Hemisphere, it’s winter when El Niño typically peaks.) Nigeria, Indonesia and Sudan are expected to have the most additional heat deaths, tens of thousands in each country, according to the report.

In the U.S., heat-related deaths are expected to be less dramatic, but not insignificant. Between September 2026 to February 2027, the report estimates we’ll see an additional 3,500 heat deaths when compared to a normal year. The risk is by far highest in September, as a record-hot summer has lingered into an unseasonably hot beginning of fall.

Zoom into the map below to see where the most additional heat deaths are expected during the El Niño season. You can click here to open the map in a new tab.

When it comes to El Niño’s impact on the U.S., the worst heat may still be to come. Historical data shows the year after an El Niño tends be even hotter, which signals 2027 could be sizzling, Jeffrey Shaman, senior vice dean and professor at the Columbia Climate School, said.

High temperatures are especially dangerous for low-income people in cities. Urban exposure to extreme heat has already increased 200% since 1982, affecting 1.7 billion people, said Sheila Foster, a climate and law professor.

Most of the people who die from heat are indoors, Foster explained. Many have working air conditioning, but can’t afford to run it through heat wave after heat wave.

Aside from warming up the planet, El Niño threatens to have numerous ripple effects globally, from higher food prices to shipping and supply chain issues .