The through line for the western United States so far in the 2026 water year is simple: there’s very little snow. With few exceptions, the mountains of the U.S. West have seen unusually little snow accumulation since October 2025, constituting a widespread snow drought. The lack of mountain snowpack has resource managers on alert going into the warmer months. Meager meltwater can affect hydropower production, agriculture, aquatic ecosystems, and wildland fire risk.
The Upper Colorado Basin was exceptionally dry in spring 2026. This map illustrates the state of its snowpack on March 15, depicting estimates of snow water equivalent as a percentage of the 2001-2025 average. Snow water equivalent (SWE) is a measure of how much water there would be if all the snow in a given area melted at once. SWE peaked for the season around March 15 at below-average values for the time of year in most watersheds. Note that values below 8,000 feet (2,400 meters) in elevation are not shown, as snow at lower elevations often melts quickly and is therefore not representative of overall snowpack health.
To derive these estimates, researchers at the Institute of Arctic and Alpine Research (INSTAAR) combined data from instruments on NASA’s Aqua, Terra, and Landsat satellites, ground-based snow sensors, and a data assimilation model called the Land Information System. The group provides regular, near-real-time snowpack reports to water managers, government agencies, tribes, and other stakeholders in Colorado, California, and other western states throughout each melt season.
The snowpack in spring 2026 was notable not only for its low level but also for its early peak. In the Upper Colorado Basin, SWE peaks on April 6, on av …