I am in the humid places for sure. It never has been a problem for the engines. They run great. When it is hot, and not humid, then thats not bad because the engines like hot weather (to an extent). The guy at the hobby shop was telling me this. The engines will run at about 200Degrees, without prop wash, but with it they run about 180. Was he right? I don't know. But i think that was interesting.