El Niño–Southern Oscillation - Wikipedia El Niño–Southern Oscillation (ENSO) is a global climate phenomenon that emerges from variation in winds and sea surface temperatures over the tropical Pacific Ocean Those variations have an irregular pattern but do have some semblance of cycles The occurrence of ENSO is not predictable
What is ENSO? - National Weather Service The El Niño-Southern Oscillation (ENSO) is a recurring climate pattern involving changes in the temperature of waters in the central and eastern tropical Pacific Ocean
Climate Prediction Center: ENSO Diagnostic Discussion ENSO Alert System Status: El Niño Watch Synopsis: El Niño is likely to emerge soon (82% chance in May-July 2026) and continue through Northern Hemisphere winter 2026-27 (96% chance in December 2026-February 2027)
ENSO Forecast - Columbia University The latest CCSR IRI ENSO plume forecast gives a 70% chance of El Niño developing in April–June 2026 versus 30% for continued neutrality, with El Niño remaining dominant through the rest of 2026 at high probabilities of 88–94%
El Niño and La Niña - National Oceanic and Atmospheric Administration For more than 30 years, climate researchers have been puzzling about how human-forced climate change affects the El Niño Southern Oscillation (ENSO), the warm phase of which we refer to as El Niño and the cold phase as La Niña