That said, I don't seek it out. If we concentrate on the dry side of the cascades, what can we expect temperature wise, and will we still find a lot of great places to sightsee?
October is a great time here in Eastern Washington. Can get chilly at night, but still lots of sunny days.
Things to see/do:
Hanford site -- I referred o it earlier. Take a tour.
LIGO lab at Richland, also has tours. If you're interested in physics.
Wineries and tasting rooms -- by the hindreds
Hiking -- up in the Tucannon in Eastern Washington.
Palouse Falls
Dayton WA has a superb French restaurant (I kid you not!)
Fishing, if you're into that.
Very little rain in October. As snowbirds we head out to Arizona in late October.