We are from the southern part of California and so far haven't needed to use the A/C if you don't mind opening the windows. If you camp in campgrounds without electric hook-ups, like we do, then the A/C is out of the question. Even if I had a huge generator I wouldn't want to run it all the time. It breaks the peace and quiet. Even the A/C is a noisy thing. But you do have to plan where to go and when to go to avoid the heat of the season.
Actually in my lifetime of camping I really haven't needed an A/C at night. There are other alternatives such as evaporative coolers that will drop the temperature a little in dry weather, using 12v system. I bought a 12 Volt Swampy SpaceKoolr from
www.swampy.net. But I am still waiting for an oportunity to use it.