Here is semitropical Louisiana I use a dehumidifier when the coach is not being used. I store it under a canopy that avoids direct rays of the sun. The dehumidifier eliminates any problems with the very heavy, humid air down here which could otherwise lead to mold and other such consequences.
When the RV is in use, I run the dehumidifier and whatever else is appropriate: In the heat, the air conditioner does the cooling and the dehumidifier helps a lot with comfort. In the cold, the heater does the warming and the dehumidifier helps a lot with comfort, especially when cooking with propane which adds moisture as well.