Kendrick Mountain as seen from the Humphrey's Peak trailhead at the Arizona Snowbowl - Oct 2007.
A few years back, I went camping at Diamond Rock on Arizona's Black river two weeks before Labor Day and could hardly find an available campsite. Two weeks after Labor day I went back to the same place and could have camped almost anywhere. It's just astounding how a little chill in the air scares off the masses. But not us hard core campers - this is when we get serious.
The other important camping recreation issues are the fishing gets better as it gets colder, the hunting seasons are starting and hiking & biking are way better when it cools down in autumn.
The fall colors visually signal the start of the best camping season. So turn on those football game recording devices ( so you can watch the games when you get back ) and get out there and bring this fall in with a few memorable camping outings. You might even want to try a big campout.