December in Washington State presents a varied climatological picture. Western Washington typically experiences cool temperatures, abundant rainfall, and occasional lowland snow. The Cascade Mountains accumulate significant snowfall, creating a winter wonderland for skiing and other snow sports. Eastern Washington, characterized by a drier climate, sees colder temperatures, less precipitation, and greater snowfall potential in higher elevations. This diverse range of conditions within the state during the final month of the year creates unique opportunities for residents and visitors alike.
Understanding typical weather patterns for this period is crucial for several reasons. It informs safe travel practices, particularly over mountain passes. It influences the choice of recreational activities, from snowshoeing in the mountains to storm watching on the coast. Historically, December weather has played a significant role in agriculture, impacting late-season harvests and preparations for the next growing season. Accurate weather predictions are also vital for water resource management, as snowpack accumulation in the mountains is a major source of the state’s water supply.