Winston summers and Asheville summers are two entirely different creatures. Asheville would be reasonably nice in the summer, as opposed to the Piedmont/Coastal parts of NC that get, as has already been noted, unreasonably warm and humid. That said, I agree with the general consensus that fall is the time to go. The trees will be changing color, the temperatures will be fantastic. All in all, it is my favorite season, and I'm from the mountains of NC.