A series of December storms delivered a welcome boost to California’s snowpack, scientists said on Tuesday in a closely watched assessment of the state’s water resources for the year ahead.
The snowpack survey recorded a snow depth of 24in (61cm), said Angelique Fabbiani-Leon, state hydrometeorologist at the California department of water resources’ snow surveys and water supply forecasting unit. The survey was conducted at the Phillips station in the Sierra Nevada, a mountain range that covers the eastern part of the state.
The department also collects measurements with electronic instruments at other sites, and said that statewide the snowpack currently stands at 71% of average.
The measurement is the first of the season, and offers an important snapshot of the health of California’s water supply. The snowpack acts as a critical saving bank for the year ahead – essentially a frozen reservoir that provides about a third of the water used annually in California as it melts each spring and flows into rivers and streams and replenishes groundwater.
A period of warm, dry weather was recently broken by a series of heavy storms – fueled by a powerful atmospheric river – that brought record levels of rain in places such as Los Angeles and large quantities of snow in mountainous areas.
Officials said that Monday’s measurement offered a hopeful sign, but cautioned that it is too soon to know how that could affect water supplies in the coming year.
“The dry conditions and warmer temperatures in early December delayed our snow-building season, but the return of storm activity, especially in the last week, helped to build a solid base for this year’s snowpack,” said Fabbiani-Leon. “While California is in a better position now, it is still early in the season and our state’s water supply for this year will ultimately depend on a continued cadence of storms throughout winter and early spring.”
The water content of the snowpack at the Phillips station is at 50% of the average for this time of year and 21% of the average for 1 April, when the Sierra snowpack is typically at its peak, Fabbiani-Leon said.
Those levels are about half of what the state saw at this time last year, said David Rizzardo, the department’s hydrology section manager.
“The trend we’re looking at right now is more rain than snow,” Rizzardo told reporters. “We’d like to see the snow accumulation pick up by April 1 so that we’re closer to average.”
The state has built a complex system of canals and dams to capture and store the water in reservoirs for the hot, dry months when it doesn’t rain or snow. Those reservoirs are measuring at 123% of average for this time of year, Rizzardo said.
The measurements are closely watched in California, which is home to 39 million people and grows much of the country’s fresh fruit and vegetables. The health of the snowpack helps determine whether California will face challenges providing water to farms and cities during the hot summer months.
The state has grappled in recent years with swings between extremes of wet and dry. About a year ago, officials recorded a water content of the snowpack at the Phillips station of 91% of the average. In 2025, the state’s snowpack was near average just ahead of the 1 April peak and the state’s reservoirs above their historic capacity after two wet winters, following a years-long drought that forced severe cuts in water use.
