# Examples

**Calculate cumulative HDDs for 3 days. Base Temperature is 65 ° F.**

Day-1 : 50 ° F

Day-2 : 48 ° F

Day-3 : 45 ° F

**Step:1 Calculate Daily HDDs**

HDD1 = max (Tref   - Tavg) = max (0, 65 - 50) = max(0, 15° F)

\= 15 HDD

HDD2 = max (Tref  - Tavg) = max (0, 65 - 48) = max(0, 17° F)

\= 17 HDD

HDD3 = max (Tref   - Tavg) = max (0, 65 - 45) = max(0, 20° F)

\= 20 HDD

**Step:2 Sum all Daily HDDs**

HDDs = HDD1 + HDD2 + HDD3

\= 15 + 17 + 20

\= 52 HDDs

**Step:3 Interpretation**

The value of 52 HDD means that based on the chosen base temperature of 65° F there was a total heating demand equivalent to 52 Heating Degree Days for 3 Days.

Now this information can be used for energy consumption estimates, heating cost projections, and the pricing of the Weather Derivatives.

A higher cumulative HDD value implies a greater heating demand during the specified period. It indicates that the weather conditions were colder, and more energy or heating was needed to keep indoor spaces at a desired temperature.

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