I live at 6200 ft elevation in the mountains, so it can get down into the single digits. Mostly it stays in the teens or 20s and lately winters haven't been much to speak of. I just want to be prepared. Right now I don't have anything on it and will wait and see how the weather goes before I put up my tarps. Mostly I am trying to keep the snow and rain out of the run so the chickens can be in the run all the time. We used to have an open run and it was a nightmare in the winter time. Now I have a covered run and am trying to keep it fairly dry for them. I let the east side of the coop open with no plastic on it.