Touring in the Southern US in August is likely to be a miserable experience, especially for someone not use to hot, humid weather. Frankly, It's miserable even for someone who is. Pedaling up 6% grades at 4 mph when the temp is 35 C and the humidity is 90% is very much like being in a sauna.

I'd suggest you consider coming over here in October for touring in Kentucky or Mississippi. Be cooler and less chance for rain. Or if you can't delay your visit, plan on touring in the mountainous West. Without AC, the South in summer is pretty much unbearable, day and night.