United States Climate Normals, 1971-2000. Annual Degree Days to Selected Bases, 1971-2000. Climatography of the United States No. 81. Supplement No. 2

摘要

This Climatography includes annual degree days totals derived from the 1971-2000 normals. A degree day is defined as the difference between the average daily temperature (calculated by adding the maximum and minimum temperatus then dividing by 2) and some base temperature value. This publication presents annual heating degree day normals to the following bases (in degrees F): 65, 60, 57, 55, 50, 45, and 40, and annual cooling degree day normals to the following bases (in degrees F): 70, 65, 60, 57, 55, 50, and 45. The values are summarized alphabetically by station within each state or territory. The states are listed alphabetically for the contiguous United States, followed by Alaska, Hawaii, Puerto Rico, the Virgin Islands, and the Pacific Trust Territories. If the average daily temperature is below the base value, the difference is considered to be that many heating degree days. If the average daily temperature is above the base value, it is treated as cooling degree days. If the average daily temperature is equal to the base value, there are no heating or cooling degree days. For example, suppose one day the average temperature is 61 degrees F. If the base temperature is 65 degrees F, then this day has accumulated 4 heating degree days. If the next day averaged 72 degrees F, then this day accumulated 7 cooling degree days. The degree days are cumulative, so it is possible to have a large number of heating degree days and a significant number of cooling degree days (or vice versa) during a given month. Degree days can be calculated to any base, depending on the application.