Been in the 30's at night.....anywhere between 30's and 50's during the day. We keep the thermostat at 65 degrees all the time and HOPE to keep it at that all winter. My son is comfortable. I am cold. But it's tolerable with a long sleeved tee and sweatshirt during the day and do love snuggling under multiple quilts, fleece blankets and thermals at night.... Still better than the exorbitant electric costs..... we're all electric................