The average daily temperatures over one week in degrees Fahr

The average daily temperatures over one week (in degrees Fahrenheit) are 70, 67, 76, 72, 63, 52, and 79. What are the heating degree-days (HDDs) for this week?

Solution

Degree days are the difference between the daily temperature mean, and 65°F.

Temperature mean = (70+67+76 +72 + 63 + 52 + 79) /7 = 479/7 = 68.43

Degree Days = 65- 68.43 = -3.43

Since its a negative value, we call this as Heating degree days (HDD) = 3.43