Warm, dry January triggers ‘snow drought’ across the West, raising water supply concerns

PHILLIPS STATION, Calif. — The metal snow sampler hit dirt sooner than expected.

On Jan. 30, state surveyors standing in a high Sierra meadow east of Sacramento found just 23 inches of snow at Phillips Station, with enough water locked inside to equal 8 inches of liquid. For a site that serves as California’s bellwether for winter water supply, that was less than half of what is typical for late January.

“After the storms at the start of the year gave way to warm, dry conditions, those early gains we saw have flatlined or slightly eroded,” said Andy Reising, who manages snow surveys and water supply forecasting for the California Department of Water Resources.

A “snow drought” after early-season storms

The bleak reading — 46% of average at Phillips Station and 59% of average across the Sierra Nevada — capped an unusually warm and dry January that has pushed much of the western United States into what federal scientists now call a “snow drought.” The emerging deficit has arrived despite above-normal precipitation in many areas earlier in the winter and reservoirs in California sitting well above historical averages.

A Feb. 5 update from the National Integrated Drought Information System, a federal program led by the National Oceanic and Atmospheric Administration, described January as “dry” and “warm” and said it left the region with “the worst snowpack in decades.” Satellite data analyzed by federal and university scientists show snow cover across the West on Feb. 1 shrank to about 139,000 square miles — the lowest for that date in a record that goes back to 2001.

As of Feb. 1, snow monitoring networks reported record-low statewide snowpack in Oregon, Colorado and Utah. In California and Nevada, where the Sierra Nevada and other mountain ranges normally serve as critical water banks for the spring and summer, 37% of California stations and 77% of Nevada stations were classified as being in snow drought, with snow water equivalent at or below the 20th percentile for this time of year.

A rapid reversal in January

The rapid downturn marks a sharp reversal from just a month earlier.

After a series of December storms, California’s first snow survey of the season on Dec. 30 measured 24 inches of snow and 5 inches of water at Phillips Station — about 50% of average at that location. Statewide, the snowpack stood at 71% of average for that date, and by early January, additional storms had nudged the statewide snow water equivalent to about 89% of average. Major reservoirs, bolstered by three consecutive wet years, were between 120% and 125% of typical storage for the time of year.

Then the storm track shifted.

In January, a blocking ridge of high pressure — a pattern meteorologists sometimes call a “Rex block” — set up over the eastern Pacific and western United States. That system deflected Pacific storms away from California and much of the interior West and allowed unseasonably warm air to build.

Daytime highs across large parts of California ran 5 to 10 degrees above normal, with some inland Southern California locations flirting with 90 degrees. Ski resorts in the Sierra reported temperatures in the 50s, accelerating midwinter melt at low and middle elevations. At the same time, many basins across the West recorded half or less of their normal January precipitation.

“The mountains of the western United States are sporting thin winter coats in early 2026,” NASA’s Earth Observatory wrote in a late January analysis of satellite imagery, adding that recent storms had been “very wet — but very warm,” meaning much of the precipitation fell as rain instead of snow.

What “snow drought” means — and why it’s increasing

Climate scientists and water managers are increasingly using the term “snow drought” to describe these conditions. Unlike traditional drought, which is defined by a lack of precipitation, snow drought can occur even when rainfall is near or above normal. The key metric is snow water equivalent — the amount of water contained in the snowpack — and whether it falls below long-term norms.

Federal drought experts distinguish between “dry snow drought,” caused by weak storms, and “warm snow drought,” when temperatures are too high for snow to accumulate or persist. This winter’s pattern, they say, is dominated by warmth.

“This is a classic climate-change, temperature-driven, elevationally dependent snowpack deficit,” said Daniel Swain, a climate scientist who studies Western weather extremes, in comments highlighted by NASA.

Why low snowpack still matters in California

In California, officials say 2026 water deliveries from the State Water Project and federally managed Central Valley Project are likely to be relatively strong thanks to high reservoir levels. In early January, California was declared 100% drought-free on the U.S. Drought Monitor map for the first time in roughly 25 years.

But Reising and other experts stress that a thin snowpack still matters. In an average year, meltwater from the Sierra Nevada supplies about 30% of California’s annual water use, feeding rivers, reservoirs and underground aquifers through spring and summer.

“Snowpack is essentially a natural reservoir,” Reising said in media briefings following the Jan. 30 survey. “When those gains go backward in January, it’s something we have to pay close attention to.”

Less mountain snow can mean more runoff arriving earlier in the season, when reservoirs must also leave room for flood protection. That can force dam operators to release water in winter that might otherwise support farms, cities and fisheries months later. It also reduces opportunities to recharge depleted aquifers in parts of the Central Valley, where state monitoring shows roughly a quarter of groundwater wells remain below average even after recent wet years.

Impacts across the West: water, rivers, and recreation

Elsewhere in the West, the consequences may show up more quickly.

In Nevada’s Humboldt River Basin, snowpack stood at roughly 32% of median levels as of early February, and forecasts call for April through July streamflows to reach less than half of normal, raising concerns for irrigators who rely on that water. In the Colorado River headwaters in Colorado and Utah, snow deficits add to long-standing worries about balancing supplies among seven basin states and Mexico.

Recreation industries are feeling the effects as well. Ski areas across Oregon and Washington have contended with thin coverage, closed terrain and repeated rain-on-snow events at mid-elevations. Local officials and business owners in parts of the Pacific Northwest have described this as one of the most disappointing ski seasons in memory, with associated economic losses for mountain communities.

Scientists say the pattern fits with long-term trends in the region. Winters across the West have warmed over recent decades, and climate models project continued increases in temperature that will push snowlines higher, shorten the snow season and increase the frequency of years in which snow drought appears even when rainfall does not.

Can late-season storms reverse the deficit?

Water agencies are beginning to adjust. California’s Department of Water Resources has been testing more flexible reservoir operations that use improved weather and runoff forecasts to capture more water from warm, intense storms while still managing flood risk. State and local agencies are also investing in flood-managed aquifer recharge, using off-channel basins and fields to divert high winter flows underground.

Federal forecasters say there is still time for some recovery this season. Outlooks for mid- to late February favor increased chances of precipitation in parts of the West, but also lean toward above-normal temperatures, meaning some storms may again deliver more rain than snow at lower elevations. In many basins, peak snowpack typically occurs in March or early April.

Standing in the shallow snow at Phillips Station, Reising cautioned that time is limited.

“We’re not where we need to be,” he said. “We did go backwards slightly, which is not what we want to see.”

Whether late-season storms can rebuild the West’s natural snow reserves remains uncertain. What is clearer, scientists say, is that the region’s water systems, economies and ecosystems are being tested by winters that are increasingly wet — but not reliably white.