When is the middle of winter according to heating degree days? January 18.

I mostly heat by burning firewood and my wood pile has shrunken quite seriously already this year. I was wondering when the middle of the winter is from an HVAC perspective and I was surprised that I couldn’t find the answer, so I downloaded data from DegreeDays.net for the Findlay Airport weather station for the past three and a half years and did the calculations to discover that yesterday, January 18, was the middle of the winter for Ohio according to the local data.

This year has been a milder than the average for the past couple years which means that I’ve been burning through our firewood faster than usual. Anyhow, if you are wondering how much more firewood you will need for the rest of the year and you know how much firewood you have burnt so far this year, it should be about half of the total amount you will burn for the entire heating season if the rest of the year continues on the same trend.

So we just passed the median day of winter’s heating needs.

(Actually, the rest of this year is more likely to regress to the average temperatures (which are just a bit colder) and so we probably aren’t really quite half way through the fuel we will burn this particular year given that the first half of the heating season has been particularly mild, but this is halfway for the average year.)