A powerful Super El Niño event is projected to drive approximately 857,000 additional heat-related deaths worldwide between June 2026 and March 2027, according to the Climate Impact Lab’s El Niño Heat Mortality Tracker.
Of these, roughly 373,000 are expected in the six months from October 2026 through March 2027. Nigeria tops the rankings with an estimated 56,100 additional deaths in that period, narrowly ahead of India.
These figures represent excess mortality above a historical baseline (roughly 1996–2005 or similar recent averages), not confirmed fatalities already recorded.
They stem from combining seasonal temperature forecasts with statistical relationships between heat and death rates across more than 24,000 regions worldwide, accounting for local climate, population vulnerability, and adaptive capacity.
Researchers describe the event as a “postcard from the future,” delivering temperatures that climate change is expected to make more common within a couple of decades.
The burden falls overwhelmingly on the Global South. Africa and Asia dominate the highest-risk list, with tropical and Sahelian countries especially exposed because of high baseline temperatures, limited cooling infrastructure, outdoor labour, and constrained healthcare systems.
The Sahel region alone has been flagged for tens of thousands of additional deaths in overlapping forecast windows.
Top projected additional heat-related deaths (October 2026 – March 2027)
Here is the ranked list of the 50 countries facing the highest projected tolls, drawn from the Climate Impact Lab tracker as reported in recent coverage:
- Nigeria – 56,100
- India – 55,200
- Indonesia – 29,300
- Brazil – 19,500
- Sudan – 14,700
- Thailand – 12,200
- Democratic Republic of the Congo – 11,300
- Chad – 11,300
- Philippines – 11,100
- Niger – 8,400
- Vietnam – 8,300
- Ghana – 7,000
- Burkina Faso – 6,900
- Bangladesh – 6,700
- Mali – 6,700
- South Sudan – 6,500
- Ethiopia – 6,000
- Cameroon – 5,900
- Benin – 5,200
- Cambodia – 4,500
- Mozambique – 4,500
- Uganda – 4,200
- Côte d’Ivoire – 4,000
- Tanzania – 4,000
- Togo – 3,600
- Venezuela – 3,600
- Somalia – 3,400
- Colombia – 3,300
- Myanmar – 3,200
- Kenya – 2,800
- Ecuador – 2,500
- Peru – 2,300
- Angola – 2,200
- Guinea – 2,100
- South Africa – 1,900
- Madagascar – 1,800
- Malawi – 1,700
- Malaysia – 1,700
- Senegal – 1,700
- United States – 1,700
- Zambia – ~1,700
- Central African Republic – 1,500
- Sri Lanka – 1,400
- Mexico – 1,300
- Haiti – 1,100
- Sierra Leone – 1,100
- Zimbabwe – 1,100
- Nicaragua – 890
- Yemen – 880
- Pakistan – 820
Nigeria’s leading position reflects both its large population and the intensity of projected heat across much of the country, particularly in northern and central regions. India follows closely, with many of its projected deaths concentrated later in the period (around March).
Indonesia, Brazil, and several Sahel and West African nations round out the top tier. Even higher-income countries such as the United States appear on the list, though at far lower absolute numbers.
Earlier projections released in September 2026 estimated around 451,000 additional deaths through February 2027. The upward revision to roughly 857,000 incorporates March data and warmer-than-expected temperatures in August and September.
The World Meteorological Organization has described the current El Niño as exceptionally strong, with sea-surface temperature anomalies in the Niño 3.4 region forecast to average around +3.7°C above normal in late 2026 and potentially set new records.
Heat is the deadliest form of extreme weather, yet mortality is often under-counted because deaths are frequently attributed to underlying conditions such as heart or respiratory disease rather than the heat itself.
Vulnerable groups — young children, older adults, outdoor workers, and people with limited access to cooling or clean water — face the greatest risk. Compounding factors such as drought, food insecurity, and strained health systems in many of the highest-ranked countries could amplify the toll.
Researchers emphasise that the projections are not inevitable. Targeted interventions — early-warning systems, public cooling centres, adjusted work schedules for outdoor labour, expanded access to hydration and shade, and strengthened emergency healthcare — could reduce deaths by tens of thousands if implemented quickly.
The Climate Impact Lab’s tracker is designed precisely to help prioritise such efforts by identifying the most affected regions at state or provincial level.
The Super El Niño of 2026–2027 is already reshaping global weather patterns, intensifying heat in many tropical zones while altering rainfall and heightening risks of wildfires and drought elsewhere.
Its human cost, concentrated in countries least responsible for historical greenhouse-gas emissions and least equipped with adaptive infrastructure, underscores the unequal burden of a warming climate.
As temperatures that once seemed exceptional become more frequent, the coming months offer both a stark warning and a narrow window for action that could still save lives.
