El Niño is surging toward a very strong peak—and its effects could last into 2027

The forecast has become unusually certain

El Niño is already established in the tropical Pacific and is expected to strengthen into a “very strong” event, peaking around the end of 2026, the World Meteorological Organization said Sept. 3. WMO put the likelihood of the pattern persisting through February 2027 at nearly 100%—the most unequivocal El Niño outlook in its history. wmo

That gives governments, utilities, farmers and health agencies a longer planning window, but not a single global weather script. El Niño shifts atmospheric circulation thousands of miles from the Pacific; its effects depend on location and season, and other ocean patterns can amplify or blunt them. wmo +1

An ocean warming fast above and below the surface

The heat driving the forecast is measurable. The Niño 3.4 index, which tracks sea-surface temperatures in the central-eastern equatorial Pacific, averaged 1.5°C above normal from May through July and reached 2.0°C in July. Weekly readings later climbed to roughly 2.2°C–2.6°C. In parts of the Pacific below the surface, July and early-August temperatures were more than 8°C above average. wmo +1

That subsurface reservoir matters because it can keep feeding the event even as surface conditions fluctuate. WMO says strong agreement among ocean, atmospheric and seasonal forecast systems supports continued intensification. wmo

The next season points to heat, floods and drought

For September through November, WMO’s multi-model forecast favors above-normal temperatures across almost all land areas. Rainfall is expected to follow a classic strong-El Niño pattern, with heightened chances of heavy rain and flooding in some regions and drought in others. A developing positive Indian Ocean Dipole and a warm tropical Atlantic could change the usual regional effects. wmo

El Niño itself is a natural climate cycle, typically recurring every two to seven years and lasting about nine to 12 months. It is unfolding on a planet already warmed by greenhouse-gas emissions; scientists have not established that climate change is making El Niño stronger, but a warmer atmosphere and ocean can worsen some consequences. un

Forecasts are now a call to act

WMO says national weather services and humanitarian partners are mobilizing around early warnings for agriculture, public health, energy and water systems. The agency’s advice is deliberately local: national meteorological services remain the authoritative source for official warnings, and the next months will determine where the forecast risks become concrete emergencies. wmo