Washington Weather

Washington climate

Washington State's climate is dramatically split by the Cascade Range into two distinct regions. Western Washington, including Seattle and Olympia, has a marine climate with mild, wet winters and dry, pleasant summers. Eastern Washington is semi-arid with hot summers and cold winters, receiving far less precipitation due to the Cascade rain shadow. Seattle receives about 37 inches of rain per year, while areas in the Olympic Mountains receive over 150 inches.

The Cascade and Olympic Mountains intercept enormous amounts of Pacific moisture, producing some of the heaviest snowfall in the world. Mount Baker set the U.S. snowfall record with 1,140 inches during the 1998-1999 season. The Hoh Rainforest on the Olympic Peninsula is one of the wettest places in the contiguous United States and is one of the finest examples of temperate rainforest in the world.

Western Washington rarely experiences temperature extremes, with Seattle's average winter lows around 37 degrees and summer highs near 77 degrees. However, the June 2021 heat dome event shattered all-time records across the Pacific Northwest, with Seattle reaching 108 degrees Fahrenheit. Eastern Washington's continental climate produces much wider temperature swings, with summer highs regularly exceeding 100 degrees in the Columbia Basin and winter lows dropping below zero.