California faces a major flood warning during the holiday week. Federal weather experts have issued one of their highest alerts. Powerful storms will bring months of rain to ground that’s already wet. This puts millions of people at risk.
More than 5 million people in Southern California are under a Level 4 “High Risk” alert for too much rain. This is the top level on the federal flood scale. Another 13 million in nearby areas face moderate risk. The danger covers a wide part of the state right before Christmas.
Weather experts call this Level 4 alert rare and serious. It happens on fewer than 4% of days each year. But those days cause almost 80% of flood damage across the U.S. They also lead to more than one-third of flood deaths. Officials see these storms as a true emergency, not just normal winter rain.
On December 22, the National Weather Service in Los Angeles told people to act now. They warned that things could get bad fast when the heaviest rain hits.
Powerful Storms Hit Wet Ground
Forecasters track two strong atmospheric rivers. These are long streams of moisture in the sky. They can cause heavy, long-lasting rain when they reach land. This time, two will hit one after the other, like a train of storms. There won’t be much time for water to drain between them.
Coastal and valley spots in Southern California could get 4 to 8 inches of rain by Saturday. Foothills and mountains might see 8 to 12 inches. Los Angeles usually gets about 15 inches in a full year. Some places could get half a year’s rain in one week.
The big worry is the buildup. The second storm will hit land soaked by the first. This raises chances of flash floods, mudslides, and rivers overflowing.
North Already Feels the Impact
The storms have started in Northern California, and they’ve already caused harm. In Redding, 150 miles north of Sacramento, one person died. Rescuers found them in a car underwater. A nearby fire station got over 5 inches of rain in 48 hours. This overwhelmed drains and shows what might come south.
Emergency teams are busy elsewhere too. In Placer County, workers saved nine people from a home surrounded by rising water. Rescues like this could increase as water rushes into low areas and roads. This will happen more when storms hit crowded southern counties.
The National Weather Service extended flood watches across much of California through Friday. This covers the peak of the second atmospheric river. Even after rain slows, high water in rivers, levees, and reservoirs will keep flood risks high for days.
Burn Areas and Mountains Raise Dangers
Recent wildfires make things worse. Areas like Eaton, Palisades, Hurst, and Kenneth burned in January 2025. The intense heat changed the soil. It created a hard, water-repellent layer like a concrete funnel. Rain won’t soak in. Instead, it will rush downhill, grabbing ash, rocks, trees, and debris.
Los Angeles County ordered 383 properties below Eaton and Palisades burn scars to evacuate. Debris flows are very likely there. Those fires destroyed 16,246 homes. Now, tens of thousands in foothill areas face risks from loose dirt and shaky slopes. Southern California’s mountains will make rain even heavier. Wet air hits ranges in Los Angeles, San Bernardino, and Santa Barbara counties. It gets forced up in orographic lift. This squeezes out more rain, up to a foot in high spots.
Water from mountains will pour into canyons, streams, and rivers. This feeds valleys and coasts, causing fast floods and longer ones downstream. The storms hit during peak holiday travel. Mountain passes might close. City floods could block freeways. Officials say skip non-essential trips. Roads can flood or slide fast. State and local teams urge people in danger zones to watch updates and be ready to leave. Preparation and quick evacuations will help keep everyone safe.
Sources:
National Weather Service Los Angeles, December 22, 2025 Excessive Rainfall Outlook
Weather Prediction Center, U.S. Department of Commerce, December 23, 2025 High Risk Assessment
California Governor’s Office of Emergency Services (CalOES), December 23, 2025 Evacuation Advisory
LA County Office of Emergency Management, December 23, 2025 Property Evacuation Orders
Shasta County Sheriff’s Office, December 23, 2025 Flood Fatality Report
California Department of Forestry and Fire Protection (CalFire), January 2025 Fire Statistics Summary