The mountains are a short trip. About 60 miles from the city. If you want to hit the actual coast (not Puget Sound). You are looking a few hours each way since you have to go around the olympic mountains.
If the weather ends up being bad you can head to eastern Washington where it doesnt rain much. Lots of wine tasting in the Yakima/Zillah area.
July 9th is Porsche day at the Redmond Exotics if you are around.
Posting this from Pike Place market. Walked over from Magnolia with the family. Perfect cloud free 70 degree day