I don't know I think it is 17 or so out side with a very light snow. I fed the bolier some more coal so now the house is around 87 with the windows open. I never thought about it prior I love steamers and have my own coal boiler. After a wild 48 hours the frame work for the layout has been completed and looks great. I just couldn't stop and even worked all Friday night and got a couple of hours last night. I am ready for coffee and breakfast now.