(Cover image Long Beach, CA, 10/10/2026, from the Orange County Register. Photo by Jeff Gritchen)
If you live near the coast or below a hillside that burned, the time to prepare for El Niño in California is now. The ocean has been tearing up Southern California beaches since August, and the rainy part of the winter hasn’t even started.
Heavy surf from three eastern Pacific hurricanes has flooded streets on the Long Beach Peninsula, red-tagged 13 homes there, destroyed a home in Dana Point, and pushed Newport Beach to declare a local emergency, twice. Governor Newsom declared a statewide emergency on September 21. A stretch of Pacific Coast Highway at Crystal Cove is sitting under a giant tarp while Caltrans figures out how to keep the bluff from eroding and taking the road with it.
October 15, the National Oceanic and Atmospheric Administration (NOAA) put out its official winter outlook, and the above normal rain band now covers the whole California coast, from San Diego to the Oregon line. The next update comes November 19.
A preview of future sea level rise comes to California
El Niño predictably raises sea level along the California coast. Warm water expands and takes up more room than cold water, which raises sea level in the Pacific waters affected by El Niño. During El Niño, the trade winds weaken, and the warm water that normally piles up near Indonesia sloshes back east across the Pacific in slow pulses called Kelvin waves. During the late-October high tides, the Weather Service warned that tides in Los Angeles and Ventura counties could run as much as a foot and a half above normal.
What storm surge is. When a storm comes ashore, wind shoves water toward the land faster than it can drain back out, and the low air pressure at the center of the storm lets the sea bulge upward a little. And if that wasn’t enough, if there is heavy rain on the shore, that also drains toward the sea, further causing water to pile up. The pile of extra water is the storm surge. It is measured on top of whatever the tide is doing at the time, so a surge that arrives at low tide is a non-event and the same surge at high tide causes flooding.
On the Gulf Coast surge can run 10 or 15 feet because the sea floor slopes gently for miles and the water has nowhere to go but up. Fortunately, California’s sea floor drops off steeply, so surge there is smaller, usually half a foot to a foot and a half in a big winter storm. The point is that none of these layers is threatening by itself — it’s the El Niño bulge, the king tide, storm surge, and the wave action that add together and end up flooding streets and people’s homes along the shore.
Not to scale. Figure by TheClimateAdvisor.com
If a King Tide lines up with a storm, that’s the week your street may flood if you live near the coast. Mark the King Tides on the calendar and get prepared. Interestingly, the King Tides seem to line up with the holidays – don’t let it ruin yours.
| King tides | Dates |
|---|---|
| Thanksgiving week | November 21–28, 2026 |
| Christmas week | December 20–27, 2026 |
| Mid-January | January 17–24, 2027 |
Flooding from atmospheric rivers
El Niño shifts the Pacific jet stream south, which means storms that would normally hit Oregon and Washington come ashore in California instead, one after another. Weak El Niños don’t do much for California rain, but the very strong ones have drenched the state end to end, and this one is on pace to be the strongest on record. We got a preview during the last strong El Niño. In February 2024, Los Angeles got more than 12 inches of rain, about three times normal for the month, which resulted in flooding and landslides.
El Niño storms are warm, so you get rain instead of snow. That fills reservoirs fast, which is good, but it can also means heavy spring runoff which can overwhelm the water management infrastructure (dams, levies, storm drains, etc.). The California Department of Water Resources is already telling people to prepare for an El Niño-driven winter.
Another problem coming Spring and Summer… a wet winter grows a thick crop of grass and brush on every hillside, and by June it has dried into fuel for fires. The record-wet winter of 2016–17 was followed by the Thomas Fire and the worst fire year California had seen up to then. So the rain you get this winter is also the grass you’ll need to clear next spring. Our wildfire guide covers how to set up a defensible space on your property.
Debris flows below burn scars
Intense rain on a slope that burned in the last few years sends mud, ash, and boulders downhill at high speed. Fire strips the plants that slow water down and bakes the soil which makes it harder for the soil to absorb water. Our post on the updated USGS burn scar model explains this in detail.
The February 2010 debris flows from the Station Fire scar damaged dozens of homes in La Cañada Flintridge, and that was a moderate El Niño. Bare slopes stay dangerous for two to five years after a fire. California has a lot of recent burn scars, including the Palisades and Eaton fires from January 2025 above Los Angeles.
What to do now
No cost, this week.
- Find out which hazard is yours. On the coast, type your address into the Our Coast, Our Future flood maps, built on USGS coastal storm modeling. Below a fire scar, check the USGS debris-flow hazard maps and our Burn Scar Flood Risk Tool, which lists the big scars since 2024 and the towns below them. Inland, look up your address on the FEMA flood map, and remember the map is based on old info.
- Turn on the alerts. Wireless Emergency Alerts on your phone, plus your county’s alert system. Debris flows arrive in minutes, so a timely warning is key.
iPhone
- Open Settings, tap Notifications.
- Scroll to the bottom to Government Alerts.
- Turn on Emergency Alerts and Public Safety Alerts. If you see Local Awareness or Always Deliver, turn those on too.
Apple’s support page has the details for your iOS version.
Android
- Open Settings, tap Safety & emergency (on some phones, Notifications).
- Tap Wireless emergency alerts.
- Turn on every alert type. If you can’t find the menu, search Settings for “emergency alerts.”
Google’s page covers the variations by phone maker.
- Know two ways out that don’t cross a creek, a low spot, or a beach road.
- Video your stuff. Get your phone out and take photos and video or every room. Open drawers, open the closets, then store the pics/video in the cloud.
Low cost, this month.
- Buy flood insurance now. Your homeowners or renters policy does not cover water that rises from the street, the creek, or the ocean. The National Flood Insurance Program (NFIP) has a 30-day waiting period, and the clock starts the day you make your first payment. A policy bought this week can start paying claims in early December, ahead of the Christmas king tides and the January storms. The 30-day flood insurance rule has the details, including the post-wildfire exception.
- Find out where the free sandbags are before the storm. Most coastal cities hand them out.
- Clear gutters, downspouts, and the storm drain in front of your house. Extend downspouts 5 to 10 feet from the foundation.
- Move what matters off the ground floor, and out of the garage and/or basement, if you’re on the coast.
Medium effort, this fall.
- Coastal homeowners: talk to your city now about berms and sand placement before the November king tides. Newport Beach and Long Beach are already building them.
- Hillside and rural properties: clear culverts and roadside ditches. Most rural post-fire damage starts with a plugged culvert.
- Backup power. Winter storms take down lines. See Using a SoGen When the Power Goes Out.
- Small businesses: get inventory and equipment off the floor, and ask your agent about a business interruption rider. NFIP pays to fix the floor and nothing for the weeks you’re closed.
The ocean off the California coast is a foot higher than normal and primed for storm surge, the storm track is pointed at the state, and the first King Tides are three weeks out. Don’t let El Niño catch you off guard!