NOAA says record-breaking El Niño is now likely this fall

Federal forecasters said Thursday that a record-shattering El Niño event is no longer a distant possibility but the most probable outcome for the coming months, as ocean and atmospheric conditions in the tropical Pacific continue to intensify at a historic pace.

NOAA's Climate Prediction Center reported a 69% chance that its three-month El Niño index will reach at least 2.5 degrees Celsius during the October-through-December period, which would make it the strongest El Niño in the agency's modern record dating to 1950. The odds of a "very strong" event were raised to greater than 90%, likely eclipsing the landmark 1982-83 and 1997-98 episodes.sfchronicle

Records Already Falling

The forecast is underpinned by extraordinary conditions already unfolding in the Pacific. Sea surface temperatures in parts of the eastern equatorial Pacific were more than 2 degrees Celsius above normal in July, while the Niño 1+2 region closest to South America reached 2.9 degrees above normal. Beneath the surface, water temperatures ran as much as 10 degrees Celsius above normal at depths beyond 100 meters.sfchronicle

Australia's Bureau of Meteorology confirmed that subsurface ocean heat during July was the highest of any month on record since 1979. The Southern Oscillation Index averaged minus 29.1 in July, the most negative value ever recorded for that month — roughly four times more negative than the threshold used to declare El Niño. The latest weekly Niño 3.4 index reading stood at plus 2.20 degrees Celsius as of August 8, already past the "very strong" threshold.weatherzone

Global Ripple Effects

The strengthening event is already reshaping weather patterns across continents. Israel's Meteorological Service warned of rare August rain and possible flooding this weekend, with unusual moisture reaching from the Golan Heights to the Dead Sea — conditions forecasters linked to the "Super El Niño" disrupting normal atmospheric circulation. In Indonesia, the BMKG warned that the strong El Niño, combined with a positive Indian Ocean Dipole, is extending the dry season and elevating forest fire risk across East Java, with dry conditions expected to last into early 2027. Kenya faces a potentially early and intense October-through-December rainy season as El Niño and a developing positive Indian Ocean Dipole direct more moisture toward East Africa.ynetnews+2

Sri Lanka's Department of Meteorology said the phenomenon's effects are expected to persist until at least April 2027, with dangerous heat already gripping eastern provinces and rainfall projected to drop sharply in the near term before rebounding later in the year.adaderana+1

What It Means for California

For California, the geographic signature of this El Niño may matter as much as its strength. Unlike the 2015-16 event, when the warmest water sat farther west and failed to deliver expected storms, the current pattern is heavily weighted toward the eastern Pacific — a configuration research has linked to increased rainfall across the state. NOAA cautioned, however, that even a record El Niño would not guarantee specific weather outcomes, as seasonal rainfall still depends on the atmosphere's "notoriously chaotic behavior".sfchronicle