Strong El Niño Now Virtual Certainty — What It Means for California This Winter

Federal climate scientists say a strong El Niño is now virtually guaranteed to materialize in 2026, with NOAA's Climate Prediction Center putting the odds at 97% that the event will be either 'strong' or 'very strong' by the three-month period ending December. There's an 81% chance it reaches 'very strong' status — a category that has historically delivered some of California's most extreme weather.

For Southern California, a very strong El Niño typically tilts the odds sharply toward above-average winter rainfall, flash floods, and landslides. History offers dramatic precedents: during the 1982-83 and 1997-98 very strong El Niños, downtown Los Angeles received more than double its typical annual rainfall. The strong El Niño of 2023-24 produced the second-rainiest three-day stretch for downtown L.A. since records began in 1877, and generated hundreds of landslides across L.A. County. The connection isn't ironclad, however — the 2015-16 very strong El Niño delivered only half of L.A.'s normal annual rainfall.

The pattern is already visible in Pacific Ocean temperatures. The key stretch of equatorial Pacific waters was the fourth-warmest on record for June dating back to 1950, and NOAA physical scientist Michelle L'Heureux notes the warm pool is actively expanding eastward, already enhancing precipitation over the central and east-central tropical Pacific. The developing El Niño is expected to shift the winter jet stream south, funneling more storm systems into Southern California.

The situation is compounded by an existing marine heat wave off California's coast — one that El Niño is now expected to prolong rather than dissipate. NOAA oceanographer Andrew Leising says the offshore heat wave, which began last year, will likely intensify and expand northward in late summer or fall. A separate marine heat wave off Northern California and Oregon has been growing since May. Climate Central notes that every major ocean basin globally is currently running with unusually warm sea surface temperatures, driven by climate change layered on top of the cyclical El Niño signal.

Beyond California, the global footprint of El Niño this winter will likely mean wetter conditions across the southern U.S., southern South America, and parts of the Horn of Africa, while the Pacific Northwest, Central America, Australia, and Indonesia face elevated drought risk. The previous very strong El Niño in 2015-16 was also linked to record global temperatures in 2024, a signal that this cycle's interaction with baseline warming could again push global heat metrics into record territory.