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Expert: - 2/17/2003


Question
Could you please describe "HEATING DEGREE DAYS","COOLING DEGREE DAYS" and "NORMAL DEGREE DAYS".

Thank you,
Kerry

Answer
Kerry,
Heating degree days and cooling degree days are used by utility companies (gas, oil, electric, etc.) in determining energy output and/or energy consumption.
Here is how they are calculated:
Take the daily high and low temperature for a particular day, and add them up. Then divide by 2 to get the average temperature for the day. Take that number and subtract it from 65. If it is positive, then it is the heating degree days for that day. If the number is negative, then it is the cooling degree days for that day. For example, let's say that the high was 40 and the low was 20. Add the two up and you come up with 60. Divide that by 2 and you get an average temperature for the day of 30. Subtract 30 from 65, and you get 35 HEATING DEGREE DAYS for that day. Now let's say that the high temperature was 90, and the low was 70. Add up the two and you get 160. Divide that by 2 and you get an average temperature of 80. Now, subtract 80 from 65, and you get -15. You then have 15 COOLING DEGREE DAYS for that day.
I hope this answered your question. If so, please close out the question and give me a rating. Thanks!  

Sincerely,

Dave Dombek
AccuWeather.com

Accuweather

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Dave Dombek

Expertise

A weather enthusiast from an early age, Dave Dombek is now an AccuWeather meteorology expert.

Experience

Dave received his B.S. degree in meteorology from the Pennsylvania State University in May of 1980. Dave joined AccuWeather in July of 1980, beginning in the Snow Warning Service late that fall after his few month period of training. Within a short period of time, Dave got involved in radio broadcasting. He spent over 25 years broadcasting forecasts on radio stations throughout the Mid-Atlantic and Northeast states, and has also done newspaper forecasts and television briefings. Currently, Dave is the lead television briefer for all of AccuWeather's television clients in the northeatern quarter of the nation. In his daily forecasting routine, Dave helps coordinate the forecasts in the northeastern part of the country. He is also the Director of Forecaster Hiring and is in charge of hiring new meteorologists. Finally, Dave is the supervisor of the climatology department at AccuWeather. An avid outdoorsman, Dave enjoys hunting and trout fishing. He also enjoys watching football and is a student of history and current events. If Dave doesn't already have enough on his plate, he is married with two teenage daughters. He also leads a small Messianic congregation in the State College, Pa. area.

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