Strong El Niño Linked to Rise in Heat Deaths
A Nature Medicine study estimates global temperature-related mortality shifts during very strong El Niño–Southern Oscillation years.
Updated on Nov. 4, 2026 in Severe Weather
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A study published in Nature Medicine on November 4, 2026, quantifies temperature-related mortality associated with El Niño–Southern Oscillation variability. Very strong El Niño years are associated with a 28.87% increase in global heat-related mortality, or 107,035 additional annual deaths, alongside a 3.70% decrease in cold-related mortality.
Why it matters
The findings link a recurring climate cycle to measurable shifts in deaths from heat and cold worldwide. The authors say forthcoming El Niño events could present new public health challenges, underscoring the need for climate-informed preparedness.
The study's estimates come from integrated global temperature and mortality databases with epidemiological models, with a 95% confidence interval of 27,336 to 176,312 additional heat-related deaths per year. Its confidence intervals remain wide, and the distribution of burden shift is reported as point estimates only.
The players
Nature Medicine
A peer-reviewed medical journal published by Springer Nature that publishes research on translational and clinical medicine.
The details
Very strong El Niño years are associated with large amounts of heat released into the atmosphere, which the study links to increased heat-related deaths. Low and medium HDI countries accounted for 67.65% of the global increase in heat-related mortality, with medium HDI countries showing the largest rise at 61,863 annual deaths.
Timeline
Study published in Nature Medicine on November 4, 2026.
Very strong El Niño years, the period the mortality estimates describe.
Seasonal Patterns
The study extends the established El Niño–Southern Oscillation framework by translating its recurring Pacific temperature swings into quantified global heat and cold mortality estimates. Its finding that burden shifts from high toward lower HDI countries adds a socioeconomic dimension to ENSO-linked climate risk.
Public health agencies and local planners can use climate-informed forecasts to prepare for heat surges during strong El Niño years. Vulnerable populations in lower HDI regions may face the largest added heat-related risk, according to the study's estimates.
The takeaway
Forecasting El Niño conditions could help health systems anticipate heat-related mortality surges, particularly in lower-resource regions where the study estimates the burden is concentrated.
Further reading
Explore related coverage in the Severe Weather section for broader context on extreme temperature events.
Source note: This article includes information reported by Nature.
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