The El Niño weather phenomenon is expected to intensify further before reaching its peak in December, potentially becoming one of the strongest events recorded since at least 1950, the United Nations has warned.
The World Meteorological Organization (WMO) said the phenomenon is likely to raise temperatures across much of the world and alter rainfall patterns, increasing the risk of droughts and floods in different regions.
In its latest Global Seasonal Climate Update, the WMO said El Niño would compound the effects of human-induced climate change, creating additional challenges for communities, ecosystems and economies worldwide.
Sea-surface temperatures in the central and eastern tropical Pacific Ocean are forecast to reach exceptionally high levels during October, November and December 2026, reflecting the rapid strengthening of the event.
El Niño occurs when surface temperatures in the central and eastern equatorial Pacific Ocean become warmer than usual, triggering changes in global wind patterns, atmospheric pressure and rainfall. The phenomenon typically develops every two to seven years and lasts between nine and 12 months.
The WMO said its latest projections were based on a consensus among 13 leading national and international meteorological centres.
WMO Secretary-General Celeste Saulo said El Niño was firmly established and strengthening rapidly. Forecasts indicate an almost 100% probability that the phenomenon will continue through February 2027, with the possibility of becoming one of the strongest events observed since 1950.
Saulo explained that El Niño does not generate additional heat but releases heat stored in the ocean. She noted that the oceans are currently at their highest recorded temperatures, meaning more heat is available to be released into the atmosphere.
The index measuring sea-surface temperature anomalies in the central and eastern equatorial Pacific rose from 1.6 degrees Celsius above normal in June to 2.5 degrees above normal in August.
For the October-November-December period, the anomaly is forecast to reach approximately 3.7 degrees Celsius above normal. If realised, this would surpass the previous record of 2.6 degrees Celsius recorded during the 2015-2016 El Niño event.
The previous El Niño contributed to the exceptionally high global temperatures recorded in 2023 and 2024. The latter was the warmest year on record, with global temperatures reaching approximately 1.55 degrees Celsius above the pre-industrial average of 1850-1900.
Although El Niño generally reaches its peak between November and February, its strongest effects on global temperatures often occur later.
The current event is already affecting some regions, including Central America, where severe drought has damaged crops and caused animal deaths, highlighting concerns over the potential consequences of further intensification.
