The PNW has interesting geography: the Cascades run North/South right near the Western shore, and they catch most of the rain that the Pacific hurls at the area.
West of the mountains, it's temperate and damp. The Olympic peninsula is technically a rainforest, but the populous areas tend to get a lot of drizzle rather than heavy rain. Snow is rare at low elevations, even in winter.
East of the mountains, it's temperate and arid. Lots of power generation and agriculture on former tribal lands.
In the mountains, large national forests which allow dispersed camping.
It's not always "mild", but wherever you end up, it's usually not inhospitable. The summers have gotten much worse lately though, Seattle was a city where nobody felt the need for air conditioners as recently as 10-20 years ago. Now they sell out in the first heat wave of the summers, and new apartment buildings are starting to include them.