Western Washington, along the Pacific coast gets all the rain, the Eastern part of the state is like a desert.
I have been to the Seatlle/Tacoma area and it rained as expected, but I went to the Tri-Cities area (Pascau,, Keeniwick,Richfield) are and it looks like a desert except where they have irrigation from the Columbia River. Most of that land is reclaimed desert I was there twice in the late fall and I did not see any rain, but it was very windy most of the time I was there.
...Rich