Seasonal temperatures have finally arrived, and furnaces and heaters are being called into action. As people monitor their energy use, they might be interested in heating degree days. It is a method used as an indication of energy needs. One heating degree day is given for each degree the daily average temperature falls below 65 degrees. For example, a high of 42 degrees with a low of 16 gives a daily average of 29 degrees. With that falling 36 degrees BELOW 65 – you’ve just accumulated 36 heating degree days. The base was set 65, since that is a temperature at which the majority of people are relatively comfortable. And as those heating degree days accumulate, so do the fuel demands. You can find the accumulated heating degree days for our Mesonet stations at mesonet.ksu.edu/agriculture/degreedays.
Mary Knapp, Weather Data Library