This element was computed using data from the National Climatic Data Center's U.S. National 1961-1990 Climate Normals (NOAA, 1994b). The original data is in whole degrees Fahrenheit. This element is computed to tenths of a degree Fahrenheit. The mean monthly values were computed by taking the 30-year mean of the monthly means. The monthly means were computed from the daily values. The monthly daily temperature range value was computed from the mean of the sum of the differences between daily maximum and daily minimum temperature. The mean annual value was computed by taking the 30-year mean of the yearly means. The yearly means were computed by averaging their 12 monthly mean values. Data extracted for Arizona and 25 mile buffer.