Heating Degree Days explained

SOUTH BEND, Ind. -- A heating degree day is a measure of energy used on a singular day.

A degree day measures how much energy is used to heat or cool a building by one degree in a given day.

A day like Saturday, where the average temperature was about 46 degrees, would have 19 heating degree days, whereas yesterday had an average temp of 51 degrees, so 14 heating degree days.

Thus, we can tell that Sunday used about 25 percent less energy than Saturday to heat a building to a comfortable temperature.

So, instead of measuring how many days we need to use heating or cooling, degree days measure how much energy is used to heat us up or cool us down.