Where to Live With Low Heating & Cooling Costs

Heating Degree Days

• The amount of annual heating energy required in a specific region is measured in degree days. A specific region accumulates heating degree days whenever the average temperature for a day is below a certain threshold temperature. A standard threshold is 65 degrees Fahrenheit because most people will heat their homes when the interior temperature falls below 65 degrees F. For example, if a day in winter has a high temperature of 40 degrees F and a low temperature of 20 degrees F, the average temperature is 30 degrees F. This is 35 degrees below the threshold temperature, so this particular day contributes 35 degree days to the annual total.

Cooling Degree Days

• Cooling degree days accumulate whenever the average temperature for a day is above a certain threshold. For the sake of convenience, the standard threshold is again chosen as 65 degrees F, even though many people would not use air conditioning on a day with a low temperature of 55 degrees F and a high temperature of 75 degrees F. Because the two thresholds are the same, any day with an average temperature above or below 65 degrees will accumulate either cooling degree days or heating degree days.

Average Degree Days

• The average heating and cooling degree days for a specific region directly represent the amount of energy that will be required to maintain a comfortable temperature within the home. To find a place with low heating and cooling costs, you need to look for places that have both cooling degree days and heating degree days that are lower than most other places in the United States. A quick way to assess an area's potential is to add up the cooling degree days and the heating degree days.

Suggested Regions

• According to degree day maps published by the National Climatic Data Center, the middle of the degree day range in the United States is about 7,000 total degree days (cooling plus heating). Regions with significantly lower totals are coastal Southern California (1,500 heating days plus 500 cooling days equals 2,000 total); Hawaii (3,500 cooling days with very few heating days); coastal northern California (3,500 heating days with less than 500 cooling days); and coastal areas of Georgia and South Carolina (about 4,000 total degree days).