The World Meteorological Organization forecasts an anomaly of +3.7°C in December, exceeding all previous events. This natural climate phenomenon, amplified by warming oceans, releases unprecedented ocean heat and will disrupt global precipitation patterns through February 2027.
El Niño: What Will Its Weather Impacts Be?
The World Meteorological Organization(1) confirms a scenario to fear: El Niño has reached a record intensity since the start of modern observations. In the central tropical Pacific, sea surface temperatures exceed all historical thresholds. The Niño 3.4 index, which measures thermal anomalies in this key region, is expected to peak at +3.7°C in December 2026, surpassing the previous record of +2.6°C recorded between November 2015 and January 2016.
El Niño is a phenomenon of abnormal warming of surface waters in the central and eastern equatorial Pacific. Contrary to a common belief, it is a natural cycle that occurs every two to seven years and typically lasts between nine and twelve months. Warm waters migrate from the western Pacific toward the east, reversing the usual trade winds. The repercussions extend far beyond the ocean: they alter rainfall patterns in South America, drive droughts in Southeast Asia, and disrupt atmospheric currents as far as Africa.
This ocean warming disrupts the atmospheric balance. Hot, humid air above the warm waters rises, creating low-pressure zones. Winds change direction, weakening the trade winds that normally push warm surface waters toward the west. Consequently, the usually dry areas of the central Pacific receive heavy rainfall, while Indonesia and Australia face droughts. The World Meteorological Organization explains that these disturbances affect marine food chains, agricultural yields, and even cyclone tracks.
Unprecedented Ocean Temperatures in October 2026
The warming intensifies. In June 2026, the Niño 3.4 index stood at +1.6°C above normal. By August, it reached +2.5°C. Projections for October–December 2026 point to an anomaly of +3.7°C, far surpassing the historic El Niños of 1982-1983, 1997-1998, and 2015-2016. According to the Japanese Meteorological Agency, conditions reached their “highest intensity ever recorded,” with temperatures locally 4°C above normal in some monitoring areas.
Celeste Saulo, the Secretary-General of the World Meteorological Organization, explained at the recent Global Heat Forum (held October 6–8, 2026 in Bangkok) that El Niño does not create new heat – it releases heat that the ocean has already stored beneath the surface. The ocean from which it draws its warmth is the hottest it has ever been measured, providing more heat to release. In normal times, cooler waters upwell along the coasts of South America, keeping the surface relatively cool. With El Niño, this mechanism weakens or reverses.
According to the Copernicus Climate Change Service, the sea surface temperature reached 29.70°C in September 2026 in the Niño 3.4 region, smashing the peaks of previous major El Niños. Globally, the average sea surface temperature was 21.05°C that same month, exceeding the September 2023 record of 20.92°C. These figures show that the oceans are absorbing more than 90% of the excess heat linked to human-caused warming, making them gigantic thermal reservoirs from which El Niño 2026 draws.
El Niño: An Impact Amplified by Global Warming
The oceanic thermal context explains the extraordinary scale of the event. In September 2026, the global ocean temperature was 21.05°C, or 69.89°F, about 1.63°C (2.93°F) above the pre-industrial average (1850-1900). The seas have never stored so much energy. Carlo Buontempo, director of the Copernicus Climate Change Service, warns that we are entering a new era of months above 1.5°C, and with a strong intensifying El Niño, this could last into 2027. Crossing the long-term Paris Agreement threshold is only a matter of time.
The World Meteorological Organization coordinates thirteen forecasting centers, and their consensus is unanimous: not only is El Niño firmly established and strengthening rapidly, but the probability is almost certain that it will persist through February 2027. The numerical models integrate satellite data, oceanic buoys, and real-time atmospheric observations.
Droughts, Floods and Other Climate Impacts Will Be Felt Sharply This Year
The World Meteorological Organization’s forecasts show that the central and eastern Pacific, the Horn of Africa, and certain coastal areas of Asia will experience above-normal rainfall. In contrast, the western Pacific, the equatorial Atlantic, the Indian subcontinent, Central America, and parts of the Caribbean will face marked rainfall deficits. These anomalies influence crops, drinking-water supplies, and fire risks. Indonesia and Australia fear prolonged droughts, while Peru and Ecuador brace for potentially devastating floods.
The cascading effects are expected to ripple through the global economy. Droughts reduce rice yields in Southeast Asia, threatening the food security of billions. Peruvian fisheries, among the world’s most productive, collapse when cold, nutrient-rich waters disappear. Commodity prices swing violently, and insurance companies reassess exposures to natural disasters.
Read also
An historic El Niño is coming: here’s what it could upend this fall
- https://wmo.int/news/media-centre/sea-surface-temperatures-reflect-strengthening-el-nino
