My wife and I have recently moved into a fairly "wet" winter environment. (Wet fog and drizzle daily.) As we are not completely settled, my gunpowder has been relegated to storage in less than an ideal place.
The powder is safe and dry, (indoors but subject to out door temps - garage) but I am curious about what affects the cool/cold humid ambient air of winter will have on it, if any. I have both black and smokeless, some of it has been opened, most of it has not. Will the powder draw moisture from the air?.... enough to cause problems?

Thanks,
Hayseed