I guess it does get a little colder here in Mississippi than it does in Jax, but it is always hot here. Seems like we have two seasons, summer (which lasts about 8 months) and fall (which lasts about 4 months). I don't think there is ever a winter.
Every time I've stayed at Fort Wilderness it has been either july or august. That is serious heat, but since my family was always up early and in bed late all we could do was just pass out from being so tired and never really give a thought to the heat.
I looked at the weather for next week and it seems like it is going to be great camping weather with the highs in the low 70s and lows in the mid 50s. What loop are you going to be camping in?