A strong El Niño event could cause an estimated 451,000 additional heat-related deaths worldwide between now and February 2027, according to a recent climate study. Researchers at the University of Chicago’s Climate Impact Lab combined temperature forecasts with research on how heat affects death rates across more than 24,000 regions globally to project the death toll of the super El Niño.
Sahel Region Faces Greatest Loss of Life
The highest number of fatalities resulting from the heat of the strong El Niño is expected to occur in Africa’s Sahel region. The Sahel is a 3.05 million square kilometre belt of dry land stretching from the Atlantic Ocean to the Red Sea, sitting between the Sahara Desert and tropical savannas. It cuts across parts of Mauritania, Mali, Niger, Chad, Nigeria, Sudan, Senegal, and Eritrea. According to the research team—which includes Michael Greenstone, Tamma Carleton, Genevieve Maricle, and Emily Grover-Kopec—some of the largest temperature anomalies across the globe over the next six months will occur across the Sahel, driving higher mortality impacts than other regions.
Did you know? In low-income countries, the additional electricity used per person during periods of high heat would only suffice to power a single LED light bulb for four months, which is far too little energy to operate an air conditioner.
Four Countries Bear the Heaviest Toll
The research projects that four countries—Nigeria, Sudan, Niger, and Chad—will experience 66,800 additional heat deaths combined, from September 2026 through the end of February 2027. Nearly half of those casualties, totaling 31,400, are projected to occur in Nigeria. With a population of 237.5 million, Nigeria is the most populous of the four and stands as the country most likely in the world to record the highest heat mortality under the super El Niño. Sudan follows with 17,500 projected heat-related deaths, Niger with 10,000, and Chad with 8,000.
| Country | Population / Poverty Context | Projected Heat Deaths |
|---|---|---|
| Nigeria | 237.5 million residents; over 60% below poverty line (2025) | 31,400 |
| Sudan | Estimated 57% in extreme poverty (2025); war-damaged infrastructure | 17,500 |
| Niger | 41% below poverty line (2021); 21% with electricity access (2024) | 10,000 |
| Chad | 44.8% in poverty (2022); 13% with electricity access (2024) | 8,000 |
Poverty and Lack of Cooling Fuel Mortality
Impoverished regions face steeper death tolls than wealthier areas experiencing identical temperatures because low-income populations lack the resources to protect themselves. In Nigeria, more than 60% of people lived below the national poverty line in 2025, and even homes connected to the grid face regular power cuts. In Sudan, ongoing conflict has destroyed businesses and jobs while damaging power supplies, leaving an estimated 57% of the population in extreme poverty in 2025. In Niger and Chad, only 21% and 13% of residents respectively had access to electricity in 2024, preventing most households from running even a basic electric fan. Many residents in these nations also depend on farming, leaving them acutely vulnerable to droughts and ruined harvests.
How Researchers Calculated Heat Mortality
To establish these estimates, the research team used seasonal weather forecasts from the European Centre for Medium-Range Weather Forecasts to predict temperature deviations over a six-month window. They paired this data with peer-reviewed Climate Impact Lab methodology, which evaluates how temperature shifts alter death rates across 24,378 distinct regions. The model accounts for local climates, population vulnerability, and coping capacities, comparing expected outcomes against regional averages recorded between 1996 and 2025.
Vulnerable Populations and Mitigation Strategies
Older adults over 65, children aged zero to four, individuals with chronic health conditions, and outdoor workers like farmers face considerable danger. Across 18 countries trapped in a combination of extreme heat and minimal cooling access—mostly concentrated in northern sub-Saharan Africa, including Niger, Mali, Burkina Faso, and Chad—governments must take immediate steps. According to the team’s Adaptation Inventory, effective near-term measures include early warning systems paired with heat action plans, targeted health outreach for vulnerable groups, cooling centres, hydration stations, and protections for outdoor workers during peak temperature hours. Public hospitals should prepare for surges of sunstroke and heatstroke patients by securing medical supplies and hiring extra staff now.
Frequently Asked Questions
Which countries are projected to experience the most heat deaths during the super El Niño?
Nigeria, Sudan, Niger, and Chad are projected to suffer the highest mortality rates, with Nigeria facing an estimated 31,400 additional heat-related deaths.
Why are low-income countries hit harder by extreme heat?
Impoverished nations lack the financial resources, grid reliability, and electricity access needed to power cooling devices like air conditioners or even electric fans.
What measures can governments take right now to save lives?
Governments can deploy early warning systems, establish hydration stations and cooling centers, protect outdoor workers, and prepare public hospitals for patient surges.
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