The World Health Organization has classified the anticipated health impacts of the 2026–2027 El Niño as a health emergency and is introducing a Grade 3 response, according to the World Meteorological Organization’s climate report. The report describes this as the first time WHO has applied such a classification to an El Niño event.
Grade 3 is one of WHO’s highest readiness levels, requiring substantial or maximum resources to address the crisis.
The WMO published its annual climate report at COP31, the United Nations’ annual climate conference, where El Niño is a major topic this year. Experts fear that a super El Niño combined with global warming could bring extreme weather capable of triggering a severe worldwide health crisis.
El Niño is the periodic, abnormal warming of tropical Pacific surface waters. Scientists have warned for months that it changes weather patterns around the world.
Researchers stress that the biggest danger isn’t simply the strength of El Niño itself, but that its effects compound those of an already warmer climate system. The WMO forecasts that 2026 is on course to be one of the four hottest years ever recorded and says it’s increasingly likely that 2027 will set a new temperature record.
The organization expects the current El Niño to multiply health risks. Increasing heat, drought and heavy rainfall could contribute to heat-related illness and deaths, poor air quality from wildfire smoke, malnutrition and food insecurity, and injuries. They could also raise the risk of waterborne and vector-borne diseases, including cholera, malaria and dengue. Vectors are living organisms that transmit disease.
Sea-surface temperatures in the central and eastern Pacific have been rising at an exceptional rate since May. The WMO announced the development of El Niño in early June, and its current forecasts suggest the event could become the strongest on record by December.
