I know of guys who keep most of their stash in a shed or garage (where it at least doesn't get rained on), and then bring it into the climate controlled shop about 6 weeks before they want to use it. I've got maple, etc, in my garage where it doesn't get wet but is subjected to high summer humidity and freezing cold in winter, but that doesn't seem to cause any problems with it, that I can tell.
Yes, best bet is to have a small shop that you can easily get a handle on the climate control (yeah, I know some of you guys have quite an idea climate, but you might want to keep quiet about it, or the rest of us might decide to pull some kind of "eminent domain" on you. hehe)