Look at California’s Sierra Nevada mountain range from October through June, and you’ll typically see quite a bit of white stuff adorning its peaks. Same goes for Oregon and Washington’s Cascade range.

But it’s March, smack-dab in the middle of the snowy season, and the snow hasn’t come. Across both ranges, snowpack levels are nowhere near historical averages. That could spell trouble in the dry summer season, when melting snow is needed to feed rivers and streams that supply cities, farms, and wildlife with water.



The Cascade and Sierra Nevada mountain data collection points are color-coded to show the percentage of snowpack on March 1, compared to their historical median. Most spots are at less than half of their normal levels, and some have less than 25 percent of their regular snowpack levels for this time of year. (Map: USDA Natural Resources Conservation Service)

How bad is it? U.S. Department of Agriculture officials reported on Wednesday that some snowpack monitoring sites for the first time recorded zero snow on March 1.

“Nearly a third of our SNOTEL sites in the Cascades and Sierra Nevada are reporting the lowest snowpack ever measured,” said Cara McCarthy, a USDA hydrologist. “These areas can expect reduced summer stream flow.”

While the Cascades have seen normal amounts of precipitation this year, it’s been in the form of rain, not snow. More than 100 high-temperature records were broken in Oregon in the month of December, and another 114 high-temperature records were broken in February, according to the National Oceanic and Atmospheric Administration.

Recent storms have helped alleviate dry conditions in some Southwestern states, but overall, the region remains in drought, with the majority of California classified as in “exceptional drought.”

California’s reliance on mountain snowpack—which provides about one-third of its water—is leaving the state vulnerable as snowstorms are being replaced with rain as climate change accelerates.

A recent NASA study found that by the end of the century, droughts in California could last as long as 40 years.