WMO: El Niño firmly established and likely to intensify into a very strong event through Feb. 2027

The World Meteorological Organization said Thursday that El Niño is now firmly established, is expected to intensify into a very strong event in the coming months, and has a near-100% chance of lasting through February 2027 — a forecast that points to months of unusually warm conditions worldwide.

The U.N. weather agency said updated multi-model forecasts show an increased likelihood of above-normal temperatures across almost all land areas for September through November 2026. It warned that a very strong El Niño raises the risk of heatwaves, droughts, floods and wildfires, even though local outcomes can vary widely. “El Niño in Spanish means boy child – but it has the potential to deliver a massive blow to communities and economies across the world. We are already seeing disruption and devastation from droughts and floods and we expect these impacts to increase as El Niño intensifies,” Celeste Saulo, the WMO secretary-general, said in a press release.

The latest ocean data show why forecasters are increasingly confident. The WMO said the Niño 3.4 sea-surface temperature anomaly — a key measure of warming in the central tropical Pacific — averaged about 1.5 degrees Celsius above normal in May through July 2026 and reached about 2.0 C in July alone. Weekly values from late July to mid-August ran roughly 2.2 C to 2.6 C above average. Beneath the surface, the agency said, exceptionally warm anomalies exceeded 8 C in some areas, a reservoir of heat that supports further strengthening.

Other major forecasting centers are seeing the same trend. The U.S. Climate Prediction Center, part of the National Oceanic and Atmospheric Administration, said on Aug. 13 that El Niño is strengthening and there is a greater than 90% chance of a very strong event during Northern Hemisphere fall and winter 2026-27. NOAA’s forecasters also estimated a 69% chance that the October-December 2026 three-month Relative Oceanic Niño Index, or RONI, will reach 2.5 C or higher — a level that would exceed previous post-1950 events on that scale if it occurs.

Australia’s Bureau of Meteorology added to that picture this week. On Sept. 1, it reported a weekly relative Niño3.4 index of 2.45 C for the week ending Aug. 30, along with a 30-day Southern Oscillation Index of minus 14.6, a reading consistent with El Niño. The bureau said models point to continued warming through the Southern Hemisphere spring and that the event is expected to persist into autumn 2027.

El Niño is the warm phase of the El Niño-Southern Oscillation, or ENSO, a natural ocean-atmosphere pattern in the tropical Pacific that typically develops every two to seven years and often peaks between November and February. The strongest modern benchmark events are commonly cited as 1982-83, 1997-98 and 2015-16, and the latest forecasts suggest the current episode could rival that class, or even exceed it on some measures. Different agencies use different ENSO metrics — including ONI, RONI, weekly Niño3.4 and relative Niño3.4 — so reported values can differ slightly without contradicting one another.

The WMO also said a positive Indian Ocean Dipole is expected to develop, with a seasonal mean near 0.9 C for September through November, a factor that can reinforce or alter typical El Niño impacts in some regions. The agency stressed that El Niño is a natural climate phenomenon and is not caused by climate change, but that it is unfolding on top of long-term human-caused warming, which raises the baseline for heat and can worsen impacts.

The WMO said it is stepping up coordination with national meteorological and hydrological services and other partners to provide climate intelligence for humanitarian, agriculture, health, energy and water sectors. For local forecasts and warnings, it said, national weather agencies remain the authoritative source.