
ALT Page 1 of updated El Nino fact sheet by Daniel Swain at UC ANR (November 2026). The initial text reads: "What is El Niño, and how can it affect California? El Niño is an episodic warming of the eastern tropical Pacific Ocean that releases stored ocean heat into the atmosphere, affecting global weather patterns. El Niño intensity is defined by the magnitude of unusual warmth of tropical ocean waters in a region west of the Galapagos Islands (i.e., the Niño 3.4 region, Fig. 1). El Niño does not “come to” or “arrive in” California—nor is it defined by storminess or rainfall. El Niño can have weather, climate, and oceanographic effects in California. When El Niño is sufficiently strong and ocean warming is concentrated in the eastern tropical Pacific, it can temporarily raise sea level along the California coast and shift the storm track toward the state, potentially raising the risk of both coastal and inland flooding..."

ALT Page 2 of updated El Nino fact sheet by Daniel Swain at UC ANR (November 2026). The initial text reads: "What is the current status of and forecast for El Niño? As of early November 2026, El Niño is already among the strongest—if not the strongest—on record for this time of year, with further intensification expected. Ocean surface temperatures are now much warmer than average along most of the California coast, and are 8 to 10°F warmer than average (record warm) from about Pt. Reyes (Marin County) southward to and past San Diego (Fig. 1). Due to a combination of El Niño-related warming (leading to thermal expansion of seawater) and alongshore water surges (i.e., “Kelvin waves”), along with the lingering effects of a pre-existing marine heatwave, California coastal water levels are already running as much as 1-2 feet above predicted astronomical tides. The 2026-2027 event is very likely (>80%) to become the strongest on record using NOAA’s official climate change-adjusted..."



































