Having grown up in Gainesville, FL (a drained swamp, I think!), I don't feel right if it isn't humid. I live in the Atlanta area, and I always notice when I get out of the car for gas somewhere near Valdosta that the air finally feels right. I would love to move back to Florida, but I don't know how much longer it will be there. When my mom grew up in Miami, there were as many trees (Oaks and such) as there still are in North Florida, where it now looks like southern California (few trees) because so many areas have been clear cut and exotic landscaping bushes brought in. Unfortunately, Floridians are being driven North due to the loss of the land they grew up in. Now it's just New York south. I just hope the snowbirds somehow miss the northern part of the state and leave it in its current "threatened" state rather than completely destroyed like the southern part.
As for the weather, I think a Californian would find it difficult to adapt for a while, but you just need to get used to being a little damp from sweat, and feeling refreshingly cool (OK, maybe COLD) as you enter an air conditioned (and dry) home or business. It seems really bad even for Floridians in May, but by July you are once again used to the stifling late afternoon damp heat. (You know, after the 4 days a week 1/2 hour deluge of rain!) I don't think anyone mentioned the rain and lightning. Florida tends to build a thunderstorm most days which breaks and dumps about 4 hours worth of steady rain in about 20 minutes, and then the sun comes back out 20 minutes later and you have 80 degree weather with wet roads.
On the bright side, there are lakes streams and rivers all over the state so you are never far from water no matter where you live. The freshwater is often forgotten due to the ocean being right there, but the springs in particular are amazingly enjoyable, and many rivers like the rainbow river are a mix of 72 degree spring water and stifling river water so you get comfortably cool water even in the middle of August. Or just go to a nearby (there is always a nearby) spring and shiver from the icy cold water!
In short, stay away, it sucks!