Steven A. Root, certified consulting meteorologist and president and CEO of WeatherBank Inc., has been studying hourly and daily temperatures in 59 hub cities dating back to Jan. 1, 1950. He calculates the cooling degree days (CDD) for each city, each day of the year. Cooling degree days are the number of degrees that a day’s average temperature is 65 degrees. May 15 to September 15 is considered the conditioning/cooling season for the U.S. and Canada.
