We live in Georgia, so it can be very hot and humid, unless you're in the mountains. Even in the mountains it can get hot, although it does get cooler in the evenings. We took a trip from Georgia to California in 2007 and honestly, we never ran into any horrors. I never made reservations more than a day in advance, except when we went up to Yellowstone. Most of the time, if it was Mon-Thurs, I just called around 3pm to find a spot we could pull into at 5:30pm. A couple times I called a day or two ahead, especially if we were going to stay more than 2 days or we were going to go into a weekend. Never once were we turned away.
Now, as far as the weather, well...anywhere you go in the South in the summer is going to be hot and humid. The Southwest will be very hot during the day and cooler at night. It's a dry heat, but once you're at 106 degrees it doesn't matter. Anywhere near a beach is going to be very crowded with families. Don't even think about going to Disney World. Any holiday will bring out the crazies.
We have some very nice COEs and State Parks in GA. We have our rig parked in the mountains now, so we go up there for most summer holidays and it's fine. We have camped at many COEs and State Parks across the South and found them to be really busy during the summers. Only once did we have a problem on a weekend. It was Memorial Day weekend and every nut in Atlanta was on the water at 5:30am and went at it until almost 11pm. Most of the campers were not rowdy. I guess the biggest issue was people letting their dogs run loose or tying them up so they could bark excessively. But during the week, most campgrounds are fairly quiet.
"Those who dwell...among the beauties and mysteries of the earth are never alone or weary of life."--Rachel Carson, environmentalist, 1956
2009 Ford F250 XL
2006 Dutchmen 25F
Me & DH in non-parenting mode!