I'm in Massachusetts and we just had the snowiest winter in a looooong time. We just cut a tarp to staple onto the coop to help keep it drier, as well as stocking up the coop with straw before a big storm. The walls of the coop are just made of plywood, and the girls did great! Granted, we have BOs, RIRs, and EEs... All of which are very cold hearty.