California Declares State of Emergency Ahead of Potentially Historic El Niño Winter

California Governor Gavin Newsom declared a state of emergency on Monday 21 September to prepare the state for a potentially historic El Niño winter, his office announced.

The declaration follows forecasts of a strengthening El Niño that could become the strongest on record. Newsom's office cited federal forecasters putting the likelihood of a very strong event this autumn and winter above 90%, with a 75% chance of historic strength.

California Mobilises for El Niño

Under the emergency proclamation, agencies will position sandbags, pumps and other flood response equipment before storms arrive. The order also streamlines procurement and directs agencies to help local authorities reduce risks to vulnerable communities and essential infrastructure.

Caltrans will stage traffic control, road closure and snow removal equipment along highways considered most at risk. The California National Guard is being prepared for flood response, search and rescue, engineering and logistics missions if needed.

'We are not waiting for this season's storms to be on our doorstep,' said Caroline Thomas Jacobs, director of the Governor's Office of Emergency Services (Cal OES).

Environmental and natural resources agencies will fast-track permitting to support local work on flooding, landslides and debris flows. Natural Resources Secretary Wade Crowfoot said the aim was to accelerate preparedness work before the worst storms arrived.

What El Niño Could Mean for California

El Niño involves warmer than average sea surface temperatures in the tropical eastern Pacific, which can alter circulation and rainfall patterns. It can bring more frequent and intense storms to California, although the announcement cautions that it does not guarantee a wet winter or any particular storm. Specific local effects remain unpredictable.

Newsom's office listed possible consequences including heavy rain, strong winds, mountain snow, large waves and coastal flooding, particularly during very high tides. Flooding or rockslides could close roads, isolate neighbourhoods and interrupt electricity supplies, while homes and businesses face potential damage.

Climate change can intensify the pattern, the announcement said. It cited a study published in the journal Science in August which found El Niño events were more than 36% stronger than before the industrial era, with the trend accelerating over the past 40 years.

The announcement said California had experienced coastal flooding linked to El Niño, with raised sea levels and waves from offshore Pacific hurricanes.

El Niño Readiness Reaches Households

Cal OES has also been directed to expand accessible, multilingual information covering severe weather, flooding, evacuation readiness, emergency alerts and power outages.

Residents are being advised to register for local alerts, check flood exposure and clear drains and gutters. The guidance highlights homes and workplaces downslope of areas recently affected by wildfire, where heavy rain can increase the danger of debris flows and mudslides.

Households should plan evacuation routes and keep emergency kits ready, including medicines and supplies for pets and other animals. 'We are preparing for this El Niño early because every Californian deserves to be safe in their home, connected to their community, and protected when severe weather comes,' Newsom said.

Newsom also issued separate emergency declarations supporting recovery from three earlier severe weather events across Glenn, Humboldt, Kern, Mendocino and Santa Barbara counties, alongside a major sewage spill in Lake County.

Separately, Newsom terminated 34 open states of emergency for fires, storms and other events in 2023 and 2024 after consulting affected counties. His office said those declarations were no longer needed to support response and recovery.