CSHANNON, the cold won't hurt your planes but you may get a few more wrinkles in them. I store my planes in the garage (detached) and there are usually 3 or 4 in my trailer all year long. I have never had a problem with it. One thing I have noticed though. The planes that are covered with Monokote tend to wrinkle in the winter time but the wrinkles come back out when the weather warms up. If I shrink 'em tight in the winter, when summer comes the covering gets tighter and the surfaces warp. I learned that the hard way so I just live with the wrinkles now. Ultracote is not as bad.