El Niño 2026-27 in California, region by region
What forecasters expect where you live, what to do before the rain, and who has declared emergencies.
What it could mean where you live
Southern California
Most reliable in past El Niños. The south has had a stronger chance of a wet El Niño winter than the north [3]. El Niño usually means a wetter than normal winter across the southern third of the state [4].
El Niño's effect on rain is usually strongest in late winter, not early [3]. Los Angeles County, San Diego County and the City of San Diego have declared emergencies [5][6].
Central Coast
Highest odds near the coast. NOAA's outlook gives California's coast its best odds of above normal rain and snow, up to 50 to 60%, from December through April [2].
North Coast and Bay Area
Less reliable in past El Niños [3]. But NOAA's best odds this winter are near the coast [2]. In a very strong El Niño, heavy rain is more likely across the whole state [3], and this one could be the strongest on record, which goes back to 1950 [1].
Sonoma County declared an emergency on October 6 [7]. In Sonoma County, see Home Ready Sonoma's El Niño guide for SoCoAlert and where to get sandbags. For what past strong El Niños did to the Russian River, see The Downspout.
Central Valley and Sierra
Wetter odds this winter. NOAA's odds of a wetter than normal winter rise across California [2]. In past El Niños, the south got more of it than the north [3].
Below a burn area, anywhere
Know your slope. The state asks people to know if they live downslope of an area recently burned by wildfire [8]. Los Angeles County lists landslides and debris flows among the risks this winter [5].
Not a sure thing. Of six strong El Niños on record by 2015, only half brought above normal rain and snow statewide: 1957-58, 1982-83 and 1997-98 [4].
What to do before the rain
- Sign up for your county's emergency alerts. The state's list links to alert pages for all 58 counties [9]. Listos California explains the kinds of alerts [10].
- Look up your flood risk by address on FEMA's flood maps [11]. Check if you live downslope of a recent burn area [8].
- Decide on flood insurance now. Most homeowners and renters policies do not cover flood, and a new flood policy usually starts 30 days after you buy it [12].
- Clear gutters, downspouts and nearby storm drains, and check the roof for leaks [5].
- Plan your way out. Never drive through floodwater [8].
- Keep supplies for up to 10 days, and line up neighbors, friends or family who can help, or who may need you [5].
Where El Niño stands now
NOAA's October 8, 2026 update says El Niño is still strengthening [1].
Chances are high that it beats every El Niño on record back to 1950 [1].
NOAA's next update is due November 12 [1]. We will update this page after it.
Who has declared an emergency so far
Our list, from official sources only, as of October 12, 2026.
| Who | When | What they are doing |
|---|---|---|
| State of California | Sept 21 | Staging sandbags and pumps, readying the National Guard, fast-tracking permits for flood work [8] |
| Los Angeles County | Sept 23 | Checking flood control systems, sandbag sites, planning for evacuations and shelters [5] |
| San Diego County | Sept 30 | State of emergency declared by the county's chief administrative officer [6] |
| City of San Diego | Oct 2 | Sandbags, evacuation routes, debris removal, shoreline and bay berms [6] |
| Sonoma County | Oct 6 | Clearing culverts and flood channels, staging sandbags [7] |
News reports mention a few more cities and counties. We list only what we could confirm on an official government page. More may follow.
What El Niño is, and why it has that name
- About every 3 to 5 years, the surface of the tropical Pacific runs warmer than average and the east winds there weaken [13].
- That shifts the storm track, which is why NOAA leans toward a wetter California winter [2].
- Fishermen on South America's Pacific coast noticed the warm water often came around Christmas. They named it El Niño, Spanish for "the boy," after the Christ child [13].
- La Niña is the opposite: cooler water and stronger east winds [13].
What it means for you
- Plan for a wetter than usual winter, most of all near the coast.
- Do the cheap work now: gutters, drains, alerts.
- Near a creek, a river or a burn scar? Sort out flood insurance and your way out this month.
- Check back. We will update this page as NOAA's forecasts change.
Sources
- NOAA Climate Prediction Center, ENSO Diagnostic Discussion, October 8, 2026.
- NOAA Climate Prediction Center, 90-day outlook discussion, September 17, 2026.
- NOAA Drought Task Force, "What can California expect from El Niño?" (2015 background).
- Western Regional Climate Center, "El Niño Impacts and Outlook, Western Region," September 2015 (background).
- County of Los Angeles, Supervisor Hilda L. Solis, local emergency proclamation, September 23, 2026.
- City of San Diego, Mayor's proclamation of local emergency, October 2, 2026 (PDF).
- County of Sonoma, "Sonoma County proclaims emergency, ramps up preparations ahead of potential winter storms," October 6, 2026.
- Office of the Governor, state of emergency for El Niño preparedness, September 21, 2026.
- California Governor's Office of Emergency Services, "How To Sign Up For Alerts In Your County".
- Listos California, emergency alerts.
- FEMA Flood Map Service Center.
- FEMA FloodSmart, "Buy a Flood Insurance Policy".
- NOAA, "El Niño and La Niña" (education resources).
Forecasts change. Sources last checked October 12, 2026. The 2015 reports are background on past El Niños, not a forecast for this winter.