State of emergency declared. Governor Newsom proclaimed a statewide El Niño state of emergency on Sep 21, and Los Angeles County followed with its own emergency proclamation. Read the Governor's announcement
California resource · Winter 2026–27
A very strong El Niño is building. Get ready before the first storm.
Plain-language forecasts, a preparation checklist you can track, and the official sources to watch as the storm season begins.
What "very strong" means
Forecasters rank El Niño by how far the Niño-3.4 region of the Pacific runs above average. NOAA calls an event very strong when that reading passes +2.0°C. The current forecast points to that top band.
It's already here
NOAA moved from Watch to Advisory on June 11, 2026. Warm water is present across the east-central and eastern Pacific.
It should last
Forecast models keep El Niño going through the winter, with strong to moderate conditions still likely into spring 2027.
Strength is not a promise
A stronger event shifts the odds toward certain impacts. It does not fix where each storm lands.
What it could mean for California
NOAA's Dec–Feb outlook issued Aug 20 places California in the above-normal category for precipitation. Pick a region to see what to watch.
The 2015–16 lesson. That El Niño was nearly as strong as 1997–98, yet Southern California stayed drier than forecast because storms tracked farther north. Prepare for a wet winter and treat any single forecast as odds.
Typical El Niño winter, by month
This is the usual pattern in strong events, not a forecast for specific dates. Seasonal forecasts rarely change much before November.
Oct
Prepare
Clear drains, check roofs, build your kit, and review flood insurance waiting periods.
Nov–Dec
Storm track shifts south
The first atmospheric rivers can arrive. Soils are still dry and burn scars are most exposed.
Jan–Feb
Peak risk
Repeated storms on wet ground raise flood, landslide, and debris-flow danger.
Mar–Apr
Tail and melt
Storms wind down. Snowmelt and swollen rivers stay a concern.
Preparation checklist
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Official sources to bookmark
For warnings and evacuation orders, trust these over any summary, including this site.