This is our first fall in the home, and so we're curious how long we'll go into the season before needing to turn on the heat pump. So far, the house has stayed extremely comfortable without active heating. The average high temp for October 2015 so far is 58 F and the average low temp is 43 F. We had a night or two when the temperature dropped to 31 F, and we were still warm inside. According to a weather website, there have been 12 heating degree days in MN this October, defined as days cool enough to warrant heating. Last night our oldest boy actually said he was too warm sleeping at night. Let's blame that on heat rising to his top bunk.