El Niño Already Underway and Forecast to Strengthen Through Early 2027

El Niño conditions are already established in the tropical Pacific and are projected to strengthen more rapidly than earlier forecasts indicated. NOAA's July outlook shows a stronger event than the one issued a month earlier, with ocean temperatures across the central and eastern equatorial Pacific continuing to warm.

Subsurface temperatures are above average and ocean heat content is anomalously high in the region, according to NOAA.

NASA reported that eastward-moving waves have transported warm water beneath the surface of the equatorial Pacific. The World Meteorological Organization said seasonal-average sea-surface temperature anomalies are expected to exceed 2 °C in key monitoring regions.

Model projections from NOAA and GFDL indicate sea-surface temperature anomalies may reach 3–4 °C above average in parts of the equatorial Pacific.

NOAA stated there is a 63 percent chance the event will reach very strong status between November and January. The most rapid strengthening is likely during July through September, the WMO said. The event is forecast to peak between November 2026 and January 2027 before gradually weakening later in winter and spring.

WMO Secretary-General Celeste Saulo stated that El Niño conditions are already underway and that strengthening conditions will intensify the chances of drought, heavy rainfall, heatwaves on land, and marine heatwaves in many regions. Michael Tippett, an atmospheric scientist at Columbia University, stated that model projections are now approaching unprecedented levels.

El Niño tends to suppress Atlantic hurricane activity while favoring increased tropical cyclone activity in the eastern Pacific.