Supervisors proclaim local emergency ahead of potentially powerful El Niño season
 

REDWOOD CITY, Calif. — San Mateo County is preparing for a potentially powerful El Niño season that could bring heavy rain, flooding, landslides, coastal erosion, high winds and power outages this winter — and officials are urging residents to prepare now, too.

The Board of Supervisors on Tuesday proclaimed a local emergency to coordinate County preparations for the 2026-27 storm season and encourage residents, workers and visitors to take steps to protect themselves, their families and their homes before severe weather arrives.

“Our county staff take preparing for severe storms seriously, and we need all county residents to know that they should, too,” said Board President Noelia Corzo. “We can all take actions, now, to prepare our families and our homes; none of us should wait until there is a major storm in the forecast."

The County’s Department of Emergency Management will lead efforts to prepare for the 2026-27 storm season, working with County departments and local agencies. A new task force will bring those groups together to share information, track preparations and work with local communities. Caltrans, PG&E and other agencies may also take part.

The task force will help track preparations across the County, including efforts to clear drains and culverts, check equipment and prepare sandbag locations. It will also help ensure emergency alerts and safety information are available in multiple languages and keep County leaders informed as preparations progress and conditions change.

According to the National Oceanic and Atmospheric Administration's Oct. 8 outlook, El Niño is strengthening, with a greater than 83 percent chance of a strong to very strong event through January-March 2027. El Niño is a climate pattern marked by unusually warm ocean waters in the tropical Pacific that can bring wetter, stormier winters to California.

“This year’s El Niño has the potential to be historic in its severity and impact, should storms hit our County and our Coastline. We have the invaluable opportunity right now to lessen the damage it will cause to our health and community. Everyday counts,” said Supervisor Ray Mueller, whose district includes much of the coastline. 

“Roads may be closed, power may go out and people may find themselves cut off and isolated for periods of time. We want residents to think now about and prepare for what they'll need if that happens,” Mueller said.

The County will also encourage cities, towns, and special districts to complete their own readiness work and to amplify that message.

County Executive Mike Callagy said officials are particularly concerned about several hazards occurring at once.

“The greatest danger is not any single hazard but the combination of multiple hazardous conditions,” Callagy said. “A storm arriving on a high tide, heavy rain falling on saturated hillsides, and wind damage during flooding each compound the others.”

County officials urge residents to take the following steps now: 

• Sign up for SMC Alert at SMCAlert.info to receive emergency notifications.
• Know your risks. Find out whether your home or workplace is vulnerable to flooding, landslides or other storm hazards.
• Make a household plan. Know how to reach family members, where to go if you need to evacuate and what to do if roads are closed.
• Gather supplies. Keep water, food, medications, flashlights, batteries and other essentials available in case of extended outages.
• Prepare your home. Clear gutters and drains where safe, secure outdoor items and take precautions against flooding.
• Pay attention to warnings. Monitor forecasts, follow evacuation instructions and never drive through flooded roads.
• Check with your insurance company about adding Flood Insurance to your policy. If you rent, consider Renters' Insurance to cover any damage to your furniture, clothes, car, computer, etc.

About San Mateo County
Established in 1856, the County of San Mateo stretches from the Pacific Ocean to San Francisco Bay and includes 20 cities and rural communities. Home to more than 750,000 residents, it is one of California’s most diverse counties with an economy driven by innovation, life sciences, agriculture and international trade and travel. In addition to serving unincorporated communities, the County provides countywide services that support the health, safety and quality of life of residents. Learn more at smcgov.org.