Degree Days

Degree Day

Degree day is used to estimate the heating or cooling requirements on a given day. 

Heating degree days count how many degree days are below the base temperature (how much heating is required). HDD = 65°F - ((Daily High Temp + Daily Low Temp) / 2)

Cooling degree days count how many degree days are above the base temperature (how much cooling is required). CDD = ((Daily High Temp + Daily Low Temp) / 2) - 65°F

Growing Degree Day

Growing Degree Days (GDD) are a measure of heat accumulation used to predict plant and insect development based on temperature. GDD is calculated using a base temperature below which growth does not occur, and an upper cutoff temperature above which growth is limited.