Degree Days and Your Heating Bill

Winter is not what it used to be, and the numbers bear that out.

In the energy business, companies actually measure the amount of cold weather that each year brings using the “heating degree days” metric, and degree day counts are trending lower as the intensity and consistency of winter cold decline.

Heating Degree Days are the number of degrees that a day’s average temperature is below 65 degrees Fahrenheit. The measure identifies 65 degrees as the temperature below which indoor heating will likely be used to make a home or building comfortable. If the average temperature for a winter day is 25 degrees, the degree-day count is 40: one for each degree under 65.

The National Oceanic and Atmospheric Administration (NOAA) tracks degree days as they accumulate each year and compares them to other time periods, such as the previous year and the average of the 10 previous years. The higher the number of degree days, the colder that winter was; conversely, fewer degree days reflect a warmer winter.

As in most other recent winters, degree-day counts this year are below the 10-year average. Here is a quick look at where degree-day counts have stood around this time of year for each of the last three years for the nearest NOAA measurement sites, which are in Albany, Hartford and Worcester. These measurements reflect degree-day counts from July 1 through late February or mid-March. Note that the winter of 2014-15 was actually colder than the 10-year average