GENEVA — Scientists have warned of major potential impacts from an intensifying El Niño event developing in the tropical Pacific, with the World Meteorological Organization and U.S. National Oceanic and Atmospheric Administration issuing alerts on the phenomenon's likely effects on global weather patterns.
El Niño conditions are present and expected to strengthen into the Northern Hemisphere winter of 2026-27, according to NOAA's latest advisory issued on Thursday. The agency reported a 63% chance that the event could rank among the strongest on record since 1950.
The WMO stated there is an 80% chance of El Niño developing between June and August, rising to near or above 90% through November. Officials said the combination with ongoing climate change could amplify extreme weather events worldwide.
El Niño involves the warming of sea surface temperatures in the central and eastern equatorial Pacific, which disrupts atmospheric circulation and alters rainfall and temperature patterns globally. Typical impacts include increased rainfall and flooding risks in parts of the southern United States, eastern Africa and China, while raising the potential for drought and wildfires in regions such as Indonesia, Australia and southern Africa.
"Prepare for El Niño," WMO Secretary-General Celeste Saulo said in a statement. "It could be the strongest in decades."
Scientists noted that El Niño tends to boost global temperatures, with forecasts suggesting it could contribute to 2026 or 2027 being among the warmest years on record. The event is expected to peak later in 2026 or early 2027.
The current transition follows a period of neutral conditions after the previous strong El Niño in 2023-2024. NOAA reported sea surface temperatures in the Niño 3.4 region at about 0.7 degrees Celsius above average, with even higher anomalies farther east.
Experts have cautioned that while El Niño increases the odds of certain weather extremes, outcomes can vary by region and exact strength. The phenomenon typically lasts nine to 12 months.
As of Thursday, monitoring agencies said they would continue to update forecasts as the event evolves. Governments and organizations have been urged to use the advanced warnings for preparedness measures to protect lives and livelihoods from potential impacts including heatwaves, floods, droughts and disruptions to agriculture and water resources. Details on specific regional preparations remain under discussion by national authorities.
