The World Meteorological Organization's seasonal climate outlook, published on 26 October 2026, indicated that the El Niño event then underway could be unprecedented in strength. The Global Seasonal Climate Update projected sea surface temperatures in the tropical Pacific, the centre of El Niño, could rise to 3.8°C above average during November 2026 to January 2027. WMO declares El Niño when the anomaly in that region reaches 0.5°C. Secretary-General Celeste Saulo said the reading was off the monitoring charts used for four decades and that El Niño would peak towards the end of 2026, with impacts felt long after.

The outlook expected wetter-than-normal conditions in parts of East Africa during the October–December rainy season, and increased risks of drier conditions in Southern Africa from November. Southeast Asia faced warmer conditions and rainfall deficits, while parts of the Americas were expected to see increased rainfall and others increased drought risk, including Central America, the southern Caribbean and the Amazon.

Speaking at a joint press conference with UN humanitarian chief Tom Fletcher, Saulo said the preparedness window remained open in many regions but would not stay open indefinitely. WMO described the outlooks as seasonal rather than predictions of individual events, and said regional and national forecasts were essential.