Many people don’t think of floods as a major natural hazard in California the way they think of drought, wildfire, and earthquakes. But areas that normally don’t flood could flood this winter.
By Colin McCarthy · Updated Oct. 14, 2026
The outlook
The strongest El Niño on record for this time of year
From July through September, sea-surface temperatures in the central equatorial Pacific ran 2.16°C above normal, the highest reading for those months in NOAA’s record going back to 1950. NOAA’s Climate Prediction Center says a strong to very strong El Niño is likely to last through January–March 2027.
Strongest July–September El Niño readings since 1950Oceanic Niño Index, °C above normal
Very strong
+0.5+1.0+1.5+2.0
2026+2.16
1997+1.79
2015+1.73
1987+1.46
1965+1.27
Data: NOAA Climate Prediction Center (ONI, ERSSTv5)
49 of 51 forecast runs favor a wetter-than-normal winterECMWF seasonal forecast issued Oct. 1 · California precipitation, October–April
Wetter than normal (49)Drier (2)
144%of normal precipitation in the median run
Each dot is one run of the model. Data: ECMWF SEAS5 via Copernicus; US Stormwatch analysis
Southern California’s ocean is running about a foot above normalSea level vs. normal, Oct. 1–9 · NOAA tide gauges
San Diegosince 1906+1.08 ft+0.61 · 2015
La Jollasince 1924+1.03 ft+0.68 · 1997
Los Angelessince 1923+0.99 ft+0.60 · 1997
Santa Monicasince 1933+0.97 ft+0.65 · 1997
Oct. 1–9, 2026Previous record month
Highest of any month on record at all four gauges. Normal is each gauge’s long-term sea-level trend plus seasonal cycle. Data: NOAA CO-OPS; US Stormwatch analysis
Precipitation forecasts this far out are probabilistic. A very wet winter is favored, but below-normal precipitation is still possible. Multiple successive extremely wet months would greatly increase the risk of flooding.
The hazards
What this El Niño could bring
More atmospheric rivers
Long, narrow plumes of moisture that can stall over the state and deliver days of heavy rain.
Coastal flooding and erosion
High water levels with big surf on top can flood low-lying shorelines and eat away at beaches and bluffs.
Landslides and postfire debris flows
Soaked hillsides can give way, and burn scars can send fast-moving mud and debris downhill.
Higher snow levels
More rain instead of snow at lower and middle mountain elevations, so more water runs straight into creeks and rivers.
Checklist
How to prepare
Check off each step as you go. Each section is tagged with when to do it.
If you live near sea level, especially along the Bay or Pacific shoreline, start preparing your home now for coastal flooding this winter. Unusually high coastal water levels, with wave action on top, could lead to severe erosion and flooding.
King tides this winter
Nov. 24–262026
Dec. 23–252026
Jan. 21–222027
The year’s highest tides, on statewide dates from the California Coastal Commission. Northern California may also see them Dec. 22, Jan. 20 and Jan. 23. With sea levels already running high, a storm or big swell during these tides raises the risk of flooding.
There’s already a lot of hype around ski season, so plan for closures and potentially longer-than-usual delays. This El Niño could bring strong storms, but it doesn’t guarantee big snow.
July–September readings: NOAA CPC Oceanic Niño Index (ERSSTv5), 1950–2026.
Seasonal forecast: ECMWF SEAS5, 51-run forecast issued Oct. 1, 2026, from the Copernicus Climate Data Store. Percent of normal is measured against the model’s 1993–2016 reforecasts. US Stormwatch analysis.
Sea level: NOAA CO-OPS tide gauges at San Diego, La Jolla, Los Angeles and Santa Monica, preliminary data through Oct. 9, 2026. US Stormwatch analysis.