But don't worry too much about rain, either. As long as they're in a fast-draining medium or no medium at all like Donald's, they will do fine. Mine are out in the garden just randomly scattered on top of the soil, and through the summer rainy season, they get a daily deluge, and very high humidity but they never rot. Pretty much take care of themselves.
I think in cold weather it's more important to keep them dry.
