I'm a three season hiker/backpacker – fall, winter and spring. Except for the big trip to someplace mountainous in the summer.

Anything over 85 and hiking and camping are out, not fun at all with the humidity. I see people running when it is 100 degrees and ask myself why they don't get a treadmill for the hot months.

East of the Mississippi here. I know some people don't understand when we complain about 90 degrees here verses 114 in the desert. It's that 70-80% humidity that gets ya. Your heat exchange system is rendered useless in this muck. But that's what swimming holes are for! 90-100 degrees, count me in. Destination: swimming holes of the Daniel Boon National Forest.

32 or colder and I'm not going. This is mostly because I lack any 4th season gear. I'll fix that some day.

Only problem with summer hiking is the tourist population, so I try to avoid going out on the weekends. I go out for the peace and quiet, and after Labor Day, the Greens, Whites, and 'daks all experience a mass exodus when everyone goes back to school/work. September is THE month to hike. After that, the sleeping gets so cold. I sleep cold in my own house October-April (why do I still live in northern Vermont?), never mind a tent. Not to mention, it seems the mountain clubs are busily removing the woodstoves from shelters because people are irresponsible and set things on fire (did I mention that people are my problem? :)

That said, I still love being in the mountains in the summer--beats being in town where there's traffic and asphalt. But then, I don't really sweat unless temps are over 85* and muggy. And I don't mind sweating, just bring extra water and imagine it's a great big sauna.