March 2026 Washington Water Supply Outlook Report

Snow Water Equivalent (SWE) statewide for March 1, 2026 is at 54% of normal. Unfortunately with only 36 days left before the statewide median peak SWE (peak snowpack) date of April 5, it will take a significant change in weather patterns to make up ground.

As of March 1 within the SNOTEL network of stations in Washington, 5 were at record low SWE and 9 were at the 2nd lowest SWE for their period of record. Basin SWE conditions across the state are variable but 6 basins are well below normal (less than 50% median SWE for this date) with the Upper Yakima, Central and South Puget Sound basins recording the lowest values at 35%, 39%, and 36% SWE respectively. 7 basins are below normal (50-69% range in median SWE) and the North Puget Sound basin is slightly below normal with a SWE of 72%.

As of March 1, overall lack of snow in the mountains is still significantly influencing Water Supply Forecasts (WSFs). Although all basins in Washington have received near normal to above normal precipitation for the Water Year To Date (WYTD, Oct. 1 to Sept. 30), a snow drought (defined here) persists through most basins in Washington. If the current snowpack deficit persists through spring, most basins in Washington can expect to see below normal to slightly below normal runoff.

With only a couple of months in the snow accumulation season ahead, the March 1 forecasts are beginning to show more certainty in the relationship between current conditions and expected streamflow in late spring to early summer. Snowmelt in spring and early summer provide much of the water supply statewide for many different users and purposes. Forecasts of expected runoff assist water users and managers plan for conditions they may expect during peak summer usage.

Read the full report here

To access reports dating back to 2010, click here.