How much Washington’s snow accumulates during the annual snow season has implications throughout the year. The snowpack is considered a crucial climate-related variable in the Pacific Northwest that affects water supplies to agriculture, to fish, to hydropower production and recreation.

Washington’s rivers, lakes and reservoirs rely on the mountain snow to supply water through the summer months. The state’s agriculture and outdoor recreation industries also depend on the snowpack for irrigation and water to support salmon and other fish habitats. The annual snow season typically lasts from October to May each year.

We’re tracking this season’s snowpack through maps and charts to better understand our water supply in 2022.

CURRENT SNOW SEASON

This snow season started in November below the 1991-2020 median for most of Washington, with the exceptions of the Olympic and Northern Cascade ranges, which were slightly above normal. Warmer than normal temperatures and above average rainfall at the start of December dropped most of Washington’s basins to far below normal, especially in the southern and central Cascade range and in the eastern basins of Spokane and Walla Walla.

Western Washington snowpack was mostly above the 1991-2020 median from late December to mid January and keeping pace with last seasons snowpack. Then in late January through March rain and warm temperatures reduced the snowpack statewide.

In April, a number of storm systems with colder air temperatures moved through Washington bring rain, hail and even some snow to the lower elevations and much needed snow to the higher mountain elevations. All of Washington’s basins- especially the Lower Yakama Basin- received snow, bringing their levels up to and above the 1991-2020 median. The Lower Yakima basin had reached an extreme low level of 36% in March gained much back (83%) but is still below the 1991-2020 median.

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Late cold, spring storm systems at the start of May brought mountain snow to most of the western and southern Washington basins, increasing their snowpacks to over 100% of the 1991-2020 median except for the Yakima basin which was at only 86%. The continuing cold weather has pushed the snowpack for over half the basins at well over 150% of the 1991-2020 median by March 20, with almost all of Washington’s basin at 190% over the 1991-2020 median on May 31.

By May 31 last season, the Yakima basin had dropped to 0%. The Lower Snake basin had dropped to 6% and with the Spokane basin was down to 66%. Only The Olympic, Central Puget Sound and Upper Yakima basins were at or over 200% of the 1991-2020 median.

MAY SNOWPACK

Comparing snowpack to the past season’s for select basins on the first reading of the day. The annual snow season lasts from October to May.

APRIL SNOWPACK

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MARCH SNOWPACK

Comparing snowpack to the past season’s for select basins on the first reading of the day. The annual snow season lasts from October to May.

FEBRUARY SNOWPACK

Comparing snowpack to the past season’s for select basins on the first reading of the day. The annual snow season lasts from October to May.

JANUARY SNOWPACK

Comparing snowpack to the past season’s for select basins on the first reading of the day. The annual snow season lasts from October to May.

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DECEMBER SNOWPACK

Below-freezing temperatures from Canada, with the jet stream moving down south across California in late December, caused record snowfall in the Sierra Nevada Mountain range between California and Nevada as well as large amounts of snow in the Olympic and Cascade mountain ranges. The Kettle Range in north central Washington and Blue Mountains in southeast Washington also received much-needed snow. Eastern Washington basins were slightly more than the normal, which is better than last season, when in late December/early January they were less than the 1991-2020 median.

NOVEMBER SNOWPACK

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CURRENT SNOW LEVELS AT SNOQUALMIE, STEVENS AND WHITE PASSES

PAST SNOW LEVELS

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FIRST SNOWFALLS AT SNOQUALMIE AND STEVENS PASSES

Historically, Stevens Pass gets its first snow before Snoqualmie Pass does. At Stevens Pass, 1 inch of snow arrived on Nov. 2, 2021. The previous year, Stevens Pass had 2 inches on Oct. 11. At Snoqualmie Pass, there were 2 inches of snow on Nov. 6, 2021. The previous year, Snoqualmie Pass had 1 inch on Oct. 24.