Welcome to the PNW!
Don't be discouraged (too much) by our weather this year. This is an unusual year with very high snowpack and wet weather. Our prime backpacking season is usually a little delayed from other parts of the country, running from July-ish to October-ish, depending on where you are heading. However, when nice, this is one of the most beautiful places in the States, with temperate rain forests, alpine lakes, granite and volcanic peaks, the Pacific coast, the Columbia Gorge and so much more.
A couple of excellent resources: