The same forecast ensemble shows no runs below 1°C and one hitting 3°C, above the 1982 83 record, but the event is arriving on a planet that has already warmed 1.45°C above preindustrial.
NOAA's Climate Prediction Center has formally declared El Niño conditions in the equatorial Pacific, and the agency's latest outlook puts a 63% probability on a "very strong" event by Northern Hemisphere winter 2026-27, defined as a Niño-3.4 index above 2°C (NOAA CPC ENSO Diagnostic Discussion). That threshold would rank the event among the largest since 1950, and it is arriving on a planet already 1.45°C warmer than the preindustrial baseline that defined the 1982-83 and 1997-98 super El Niños.
The current weekly readings tell the same story the models do. The Niño-3.4 index, which captures the central-eastern Pacific where El Niño's signature is strongest, sits at +0.7°C, while the coastal Niño-1+2 index has surged to +2.1°C, with westerly wind anomalies pushing warm water eastward across the basin (New Scientist). Japan Meteorological Agency has also declared onset, according to the same reporting, and forecasters expect the event to peak in Northern Hemisphere winter and persist into 2027.
The 63% number comes from NOAA's North American Multi-Model Ensemble, a snapshot that will be revised monthly. What makes it more than a single-model projection is the spread: of roughly 200 ensemble members, none return a Niño-3.4 below 1°C for the November-January peak, several cluster near +2.6°C, and one Canadian model run hits +3°C, above the +2.5°C reached during 1982-83, the strongest event in the modern record (New Scientist). NOAA's Matthew Rosencrans, a seasonal forecaster at the Climate Prediction Center, called the setup "significant," while Met Office scientist Adam Scaife said the event has a real chance of being record-setting.
That record matters because the atmosphere it lands in is not the atmosphere of 1982-83. Global mean temperature in 2023-24, the most recent El Niño-influenced year, ran 1.45°C above the 1850-1900 baseline, the warmest single year in the instrumental record. The Met Office projects 2027, when this El Niño's peak warmth is expected to bleed into the global mean, as the next candidate for "hottest year," not 2026 (New Scientist). A +2.0 to +2.6°C anomaly in the central-eastern Pacific does not just replay a historical event. It stacks on top of a baseline that has shifted by more than a degree since the last super El Niño.
What changes in practice depends on the region, and the regional picture is one of shifted odds rather than guarantees. Wetter conditions are favored in southern California and the southern US Gulf Coast, drier conditions across the maritime continent, India, and northern Australia, and reduced summer rainfall across the southern US, per the same reporting (New Scientist). Forecast skill at 6 to 9 months is real but not high; a 63% probability is not a prediction, it is a meaningful tilt in the dice that warrants planning.
Peru, which lost hundreds of lives to flooding and landslides during the 2015-16 El Niño and saw its coastal fisheries collapse, is the standard early test. India and Australia, both already parched through 2026, face elevated odds of a failed monsoon or delayed wet season depending on the event's exact track. For forecasters, the open question is not whether El Niño is happening but whether the institutions that translate a 63% probability into regional warnings and humanitarian response have the staffing and budget to do it; the same source flags recent cuts to NOAA capacity that could thin the warning pipeline (New Scientist).
The 63% number will move. The next NMME plume, due in mid-July, will sharpen or soften that probability, and the JMA and Australian BOM will issue their own updated outlooks in the coming weeks. The most important variable is not the central-Pacific number, though. It is the year the peak warmth lands in, and 2026 is not 1998. The next super El Niño will arrive into a climate system that has already absorbed the equivalent of the entire 1982-83 anomaly as a permanent shift.