ECMWF’s updated early October El Niño forecast is extraordinary in both intensity and duration

The latest ECMWF forecasts for El Niño from early October 2026 are very striking; they indicate that it will be more intense, longer-lasting and more extensive, with the expected repercussions of this extraordinary 2026–2027 El Niño event.

Let’s review what El Niño is and the latest ECMWF forecasts.

What is El Niño?

The El Niño-Southern Oscillation (ENSO) phenomenon in the Pacific Ocean is undoubtedly the most influential climate factor on the planet. Its cycles of warm (El Niño) and cold (La Niña) waters in the central and eastern equatorial Pacific alter the release of ocean heat into the atmosphere, influencing atmospheric circulation, temperatures, rainfall and other weather phenomena that affect agriculture, wildfires and marine fisheries around the world.

Evolution of sea surface temperatures over time in the Niño3.4 region of the Pacific, with the 2026 evolution shown by the red line, going off the scale with values never previously reached in the modern era. Climate Reanalyzer

El Niño, the warm phase of ENSO, occurs on average every two to seven years and usually lasts for nine …….