The two hazards that come to my mind are moisture and animals. You don't want to store fabric any place humid or that might get wet, and you might need some sort of barrier to keep out mice and/or bugs. These things may or may not be issues depending on your circumstances, but those are the things to think about. Since it's only a few months, it's unlikely to be a large problem.
If storage were long-term then I'd also worry about exposure to light fading the fabrics. You certainly don't want to store them any place they get direct sun on them, but ambient room light probably wouldn't be an issue for such a short time (I'd be curious if anyone knows how quickly fabric can fade from light).