The climate of the United States since 1895: spatial and temporal changes.

Abstract

Time series of temperature and precipitation weighted by area and grouped by season for each of the 48 contiguous United States were analyzed. Within an 83-year period of record (1895-1977) three sub-periods or climatic regimes are identified and the differences in their means and standard deviations plotted and analyzed. The statistical significance of the changes in the mean was calculated by using a two-tailed t test; for changes in the standard deviation, the F-ratio test was used.- from Authors