Dorian J. Burnette, Ph.D.

Degree Days from High and Low Temperature

High Temperature:
°F °C K

Low Temperature:

Heating Degree Days:
Cooling Degree Days:


If the mean temperature is below 65°F, heating degree days occurred:

Heating Degree Days Equation

If the mean temperature is above 65°F, cooling degree days occurred:

Cooling Degree Days Equation

In the above equations, HDD are the heating degree days in °F, CDD are the cooling degree days in °F, THI is the high temperature in °F, and TLO is the low temperature in °F.