Howdy @Brox ! I'm excited that you'll be hiking a big stretch of the AT. We love our national scenic trails at REI and I thought I'd throw a couple of great resources your way. The "quick answer" to your question is that it varies quite a bit. 45-85 degree range depending on where you are. You can get regional weather and precipitation going back years on any number of weather-specific sites. Here's some more reading material as you plan you trip.