WMO Seasonal Update Points to Tropical Pacific Anomaly of Up to 3.8 °C

The World Meteorological Organization published a new seasonal climate outlook on 26 October 2026 stating that the El Niño event now under way could be unprecedented in strength, with tropical Pacific sea surface temperatures potentially running as much as 3.8 °C above average between November 2026 and January 2027.

The figure comes from WMO's Global Seasonal Climate Update for November-December-January 2026. For context, the organization notes that it declares an El Niño when the sea surface temperature anomaly in the tropical Pacific — which WMO describes as the epicentre of the phenomenon — reaches 0.5 °C.

"This is literally off the monitoring charts that we have used for the past four decades. El Niño will peak towards the end of 2026 but its impacts will be felt long after that," WMO Secretary-General Celeste Saulo said.

A forecast framed for humanitarian planners

The update was presented at a joint press conference with Tom Fletcher, UN Under-Secretary-General for Humanitarian Affairs and Emergency Relief Coordinator, and WMO framed the release explicitly as an input to anticipatory humanitarian work rather than as a standalone climate bulletin.

"But a powerful El Niño does not have to be a recipe for humanitarian disaster. We have the science, the forecasts and the early warning systems to save lives and protect livelihoods. What we need now is decisive action, especially to protect the most vulnerable communities," Saulo said at the briefing.

WMO states that the window for preparedness remains open in many regions, that extreme weather does not have to translate into humanitarian emergencies or casualties, but that the window will not stay open indefinitely. The organization describes its own priority as supplying science-based information so governments and humanitarian organizations can anticipate risks, prepare operations and protect vulnerable populations.

According to WMO, a very strong El Niño disrupts normal temperature and rainfall patterns across many regions — bringing severe drought to some, heavy rainfall and flooding to others, and increased heat over large areas. The organization says extreme weather events are already being observed and that it expects these to multiply and cascade as the event intensifies.

What the outlook says region by region

The WMO seasonal outlook sets out several regional signals:

• East Africa: wetter-than-normal conditions are more likely in parts of the region during the October–December rainy season, which WMO says increases concerns about heavy rainfall and flooding.
• Southern Africa: increased risks of drier conditions, which WMO says could affect crop production, water availability and livelihoods from November, the typical start of the rainy season.
• Southeast Asia: warmer conditions and rainfall deficits raise the risk of heat exposure and add pressure on agriculture and water supplies; WMO points to increases in wildfire and smoke-haze risks already being seen.
• The Americas: increased rainfall in the Northwest United States and southern parts of western South America, with above-normal precipitation also expected in North America and the northern portion of the Caribbean. WMO flags increased drought risk in parts of Central America, the southern Caribbean and the Amazon.

The limits WMO places on its own product

The organization is explicit that these are seasonal outlooks and not predictions of individual weather events. On that basis, WMO says regional and national forecasts are essential to identify where and when action is needed.

That layered approach is already visible in the system: WMO notes that Regional Seasonal Climate Outlook Forums are issuing their own forecasts, naming South Asia, the Southwest Indian Ocean and the Greater Horn of Africa among them. Readers tracking how these successive assessments have evolved can follow our running news coverage and the background material on how El Niño is measured.

The full WMO item, including a link to the recorded press conference with Saulo and Fletcher, is available on the organization's website.