January 2008 and the Degree Day

Berkshire's January, with 31 days, low sun angle, long nights, Arctic cold winds, and coastal storms represents the worst part of winter's grip on New England. The photo above was taken yesterday, and a clipper brings perhaps another half foot before nightfall today as it speeds its way over us. Temperatures are predicted to plunge to four or five Fahrenheit by morning before relative relief arrives perhaps over the coming weekend.
Such low temperatures focus residents' attention on the degree day, a heating energy unit defined as a day averaging one degree below 65F. For example, when a day averages 20F, we accumulate 45 degree days. Data for nearby Pittsfield, Mass., record an annual heating requirement of some 7,500 degree days for our area.
Although my Mother claimed that over her lifetime she had seen frost in the Berkshires in every month excepting July, our heating season runs from about the middle of October to near the end of May.
In retirement we have begun tracking our energy use. For example, in November we had 697.5 heating degree days, and in December 1,178, reflecting winter's progress over a near-average heating season so far. Relating those abstract numbers to practical energy use, our cottage by calculation used 0.161 gallon of fuel oil per November degree day and 0.139 gallon per December degree day. The lower usage rate for December despite much increased cold reflects more efficient boiler operation as it runs longer as well as some fine tuning of our antique, one-pipe steam heating system, a tinkering that we enjoy from long experience with such heating plants.
As we watch the snow create winter scenes such as the above, we are comforted by the warm shine from our old steam radiators, a warmth that increases as a relatively snowy winter deepens with the arrival of the New Year.