Direct Normal Solar Radiation Data Manual PDF Download

Monthly averaged data is presented which describes the availability of solar radiation at 248 National Weather Service stations. Monthly and annual average daily insolation and temperature values have been computed from a base of 24 to 25 years of data. Average daily maximum, minimum, and monthly temperatures are provided for most locations in both Celsius and Fahrenheit. Heating and cooling degree-days were computed relative to a base of 18.3°C (65°F). For each station, global anti K/sub T/ (cloudiness index) were calculated on a monthly and annual basis.