El Niño winter 2026–27
El Niño is here. Get ready now.
Forecasters expect one of the strongest El Niños on record this winter. Here's what that means for Larkspur, and how a sandbag wall helps.
What it is
Warm ocean, wild winter
El Niño is when the ocean along the equator in the Pacific gets much warmer than normal. That warm water changes the jet stream, which steers storms. During a strong El Niño, more and bigger storms often get aimed at California, and the ocean along our coast sits higher than usual for months.
83%+
chance of a strong to very strong El Niño lasting through Jan–Mar 2027, according to NOAA (Oct. 8, 2026)
+2.1°C
above normal in the key Pacific ocean zone forecasters watch, and still rising as of October
90–95%
confidence in a wetter-than-average California winter, from climate scientist Daniel Swain
73,000
sandbags Marin County has stocked this year. In a normal winter it uses about 5,000.
Why Larkspur
Three kinds of water, all at once
Larkspur sits where Corte Madera Creek meets the bay. That's what makes El Niño so risky here. Each of these is a problem by itself. During El Niño they can all hit together.
Rain
Bigger storms
The heaviest El Niño rain usually comes in January and February. Forecasters say North Bay watersheds like ours are more likely than not to see very wet conditions this winter.
Bay level
A higher bay
Strong El Niños in 1982–83 and 1997–98 raised California sea levels 6 to 10 inches, and it lasted from fall into spring. On Feb. 3, 1998, the high tide at the Golden Gate came in about 2 feet higher than the tide tables predicted.
King tides
Extreme high tides
Low parts of Larkspur and Corte Madera are at risk once tides reach about 7 feet. Last January the tide peaked near 8.7 feet, and the Larkspur Marina flooded. Officials expect 8-foot-plus king tides again this winter.
When the bay is already high, rainwater in Corte Madera Creek has nowhere to go. It backs up over the banks and into the streets, and garages flood first.
We've seen this before
The last super El Niño
The 1997–98 El Niño is the one people around here still talk about. February 1998 brought 14.89 inches of rain to San Francisco. All 10 Bay Area counties, including Marin, were declared eligible for FEMA disaster aid. A Marin emergency official remembered streets in Mill Valley "knee deep in water" and houses sliding down hills.
Now – November
Get set up
Coastal flood risk is already higher than normal. This is the time to get bags down, before everyone calls at once.
December
Risk climbs
Forecasters expect inland flooding risk to start rising around December, along with the winter king tides.
January – March
Peak season
The biggest El Niño storms usually hit Northern California from January through March.
How sandbagging helps
Hold the line before the water does
Sandbags won't stop a whole creek, and no sandbag wall is perfectly watertight. A wall built the right way does slow water down and turn it away, so a lot less of it gets into your garage or house. Here's what we do and why.
Plastic sheeting first
Flood guides agree that sandbags work best at doorways with a waterproof layer behind them. We lay heavy plastic under the bags and run it up against the door.
Bags turn water away
Officials recommend placing bags so they steer water, mud and debris away from your home instead of trying to dam it. We set every run with that in mind.
Pumps need walls
Larkspur is adding pumps for this winter, but its Public Works Director said pumps only work alongside physical barriers. Your sandbag wall is that barrier at your door.
Up before the storm
Sandbags only help if they're down before the water rises. We set up ahead of big forecasts and king tides, and come back to pick them up when the season's over.
Also sign up for Alert Marin for official flood warnings, and check Ready Marin for county updates.
The honest part
El Niño isn't a guarantee
The Bay Area sits between the Northern and Southern California storm tracks, so the heaviest rain could land north or south of us. The 2015–16 El Niño was very strong, and San Francisco got only about half as much rain as in 1997–98. Still, forecasters say the odds this winter favor wet. Sandbags are cheap compared with a flooded garage, so it makes sense to be ready.
Sources
- NOAA Climate Prediction Center, ENSO Diagnostic Discussion (Oct. 8, 2026)
- KQED: California's El Niño winter could be "profoundly unsubtle"
- USGS Fact Sheet 175-99: El Niño sea levels and the February 1998 Bay flooding
- Scientific American: El Niño can raise sea levels along the West Coast
- CBS Bay Area via KION: Marin County prepares for El Niño as king tides loom
- Larkspur City Council: king tide readiness, pumps and sandbags
- City of Larkspur: Flooding & King Tides
- San Francisco Chronicle: 1998 El Niño pounded an unready Bay Area
- SFBayWeather: El Niño 1997–98 vs. 2026–27
- San Bernardino County Fire: sandbag placement guidance
El Niño Community Discount
15% off your quote this El Niño season
This winter could be a rough one, and we want every neighbor protected, not just the ones who call first. Every quote for the 2026–27 El Niño season gets 15% off. No code needed. Just ask for a quote and we'll take it off the price.