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Dry conditions across Southern California in early January 2025 set the stage for a series of deadly wind-driven wildfires. burned thousands of homes and other structures in the Los Angeles area.
Minh Bana hydrologist at the University of California-San Diego Western Extreme Weather and Water Centermonitor the state's water supply. He puts Southern California's drought into context using charts and maps.
How dry is Southern California right now?
In early January, soil moisture in much of Southern California was in the bottom 2 percent of the historical record for that day in the area. That's extremely low.
Hydrologists in California watch the sky closely starting from Octoberwhen California's water year begins.
The state gets very little rain from May to September, so late fall and winter are key times to fill reservoirs and accumulate snowpack for water supply. California based The Sierra snowpack provides about one-third of its freshwater supply.
However, Southern California is starting the 2024–25 water year quite dry. This area gets rain from an atmospheric river in November, but not much. Then most of the atmospheric river hit the West Coast from October to January and turned north to Washington, Oregon and Northern California.
When the air is warm and dry, evaporation and evaporation also draws water out of plants and soil. That leaves behind dry vegetation that can provide fuel Embers fly to spread forest firesas the Los Angeles area saw in early January.
