Wildfires in California have caused devastating destruction, shrinking water supplies, and billions in lost agriculture. And now, portions of California continue to endure another potential disaster – mudslides.
- August 28, 2025
California Mudslides: When Heavy Rains Strike Fire-Scarred Terrain
Wildfires in California have caused devastating destruction, shrinking water supplies, and billions in lost agriculture. And now, portions of California continue to endure another potential disaster – mudslides.
A mudslide is a fast-moving landslide, where masses of rock, earth, or debris move down a slope, that tends to flow in channels. They happen when something disturbs the natural stability of a slope. Through drought and wildfires, the roots of vegetation along slopes are either weakened or destroyed, allowing the soil to become loose. Heavy rains, earthquakes, and volcanic eruptions can act as triggers to landslides. Mudslides typically develop when the rainfall rapidly collects in the ground.
Recent California Mudslide Events
Heavy rains in February 2024 caused devastating mudslides throughout Southern California, with nearly 500 debris flows reported across the region. Los Angeles experienced record rainfall, with downtown receiving 7.03 inches in just two days – the third-wettest two-day total since weather records began in 1877. In the Beverly Crest area of Los Angeles, mudslides damaged multimillion-dollar homes and cars, with mud measuring up to 20 feet deep in some places. Crews responded to 383 mudslides in Los Angeles alone, and seven buildings were deemed uninhabitable.
More recently, in February 2025, Southern California experienced another round of epic mudslides that were even worse than the previous year. Mudslides carried debris and cars out of neighborhoods, and a firefighter’s vehicle was swept into the ocean off the Pacific Coast Highway in Malibu. These atmospheric river storms brought staggering rainfall totals, with some areas recording over 22 inches of rain.
The Role of Atmospheric Rivers
Given that atmospheric rivers – narrow bands of concentrated moisture from the Pacific – have been delivering intense rainfall to California, mudslides and landslides have become more common. These atmospheric river events are particularly impactful because they can dump enormous amounts of rain in short periods. Atmospheric rivers create 30% to 50% of annual precipitation on the West Coast and are vital to water supplies, but can also cause storms that produce flooding and mudslides.
Recent El Niño events have been known to enhance atmospheric river activity on the West Coast. The 2024 El Niño reached rare “super El Niño” territory, contributing to California’s intense storm activity. As the climate warms, atmospheric rivers are predicted to become more extreme, with sharper increases in rainfall rates. While this increased rainfall will be beneficial given ongoing drought concerns, any rain that falls may be enough to cause more mudslides, especially in fire-scarred areas.
The Wildfire Connection
The areas most at risk are on or near hillsides that have burned in recent years, with little or no vegetation left to hold soil in place. Burning vegetation and soil on a slope more than double the rate of water runoff, and hillsides remain vulnerable to mudslides for at least three to five years after a wildfire, generally how long it takes for vegetation to grow back.
Heat, ash, and oily residue from wildfires also make it harder for water to infiltrate the top layer of soil, making the ground almost water-repellent. After recent wildfires, high-intensity fire has made soils less able to absorb water, and many of the places that burned have been denuded of vegetation and structures that help hold steep hills in place.
Historical Context and Future Outlook
This particular pattern is similar to the devastating 1997/1998 El Niño event, which caused over 30 major mudslides that were responsible for loss of life and property. On January 9, 2018, intense rain fell on a weeks-old wildfire burn scar in the mountains above Montecito, unleashing what residents remember as the “1/9 Debris Flow.” Huge torrents tore through the community, killing 23 people and destroying or damaging hundreds of homes.
Recent events show the economic impact continues to grow, with AccuWeather estimating preliminary total damage and economic loss from intense California storms reaching between $9-11 billion. Nationally, landslides and mudslides cause approximately $1-2 billion in damage and kill an average of 25 people each year in the United States.
Climate Change and Future Risk
Scientists have found clear links between the climate crisis and heavier rain. A warmer atmosphere can hold more moisture, meaning more intense rain when it falls, and climate projections suggest California will experience less frequent but more intense rainfall in the future, especially from atmospheric rivers.
Wet extremes become even wetter because there is more water vapor available in the atmosphere in a warmer world, and these atmospheric rivers that take advantage of the water vapor in the atmosphere will be stronger and wider and more intense at landfall.
Safety and Preparedness
Understanding mudslide risks and staying prepared is crucial for California residents. The places most at risk for mudslides are at canyon bottoms, stream channels, outlets of canyons, and slopes excavated for buildings. Immediate signs of a pending mudslide include tilting trees or sudden changes in rivers, especially after rain.
Modern weather monitoring systems are becoming crucial tools in mudslide prediction and warning, providing real-time data on rainfall intensity, soil moisture levels, and other critical factors that can help save lives and property.