The Olympic peninsular shields Seattle fro the north west Pacific ocean. It has a mountain range, with some of the lowest altitude glaciers for its latitude, rain forest, wild ocean coast beaches and oftem a lot of sea fog. This usually stays on the coast but can creep inland. I visited in summer, but Ruby beach was in deep fog.
The Hoh rain forest which is only a short distance inland was fairly sunny on the same day. Lake Quinalt was cloudy, but Hurricane ridge was also sunny. So depending upon where you visit, the weather is dramatically different.