From NASS
The recent wet weather patterns around the Puget Sound helped soil moisture, penetrating the dry layers from autumn. These rains refreshed the soils and reduced fire danger. The last few days of December brought wind. Most livestock were moved to higher ground or heavy-use areas. Orchards and berry plantings were pruned. CSA operations have continued production for winter hardy vegetables.
Snohomish County had flooding over Christmas week. The ground was completely saturated and there were reports of washout and erosion from the extensive rain. Yakima County received 1.2 inches of precipitation during December. No snow accumulated. The coldest nighttime temperature was 16 degrees F. All fruit trees were sufficiently cold tolerant, and little damage occurred. Winter pruning of grape vineyards and fruit trees continued at a steady pace.
Stevens County was very mild. Daytime temperatures averaged 36 degrees F while nighttime temperatures dipped to 27 degrees F. Total snow accumulation was 5.5 inches for the month of December. Ferry and Okanogan counties had colder temperatures at the beginning of the month, then trended towards above-average temperatures at the end of the month.
The Palouse had a mild December. Whitman County had saturated soils. Winter wheat, winter legumes, and rangeland were in good condition.