What are some US states with cooler summers?

I'm from GA and I'm tired of the hot humid summers. I drove to Montana a couple of weeks ago with my girlfriend but there is not much here and we are having a hard time finding a house to rent. I do love the weather though and would like to find somewhere to look with similar cool weather but not such a big empty state. I have heard about California's cooler summers but it sounds pretty expensive to live there and Maine would be to far to drive right now. Any suggestions or smaller cities that might be what I'm looking for? I do like the cool windy weather and high elevation. Probably nowhere near GA or the southeast that have cool summers.