The Climatological Relationship Between Temperatures of Successive Months in the United States

Abstract

Where significant, the relationship between mean temperatures of successive months in the United States, based on 60–80 years of data, was found to be generally of a persistent nature. Maximum persistence occurs in mid-nation in summer with secondary maxima found in the West from April to May and in the East from December to January. The geographical distribution of persistence allows tentative identification of large-scale components of the atmospheric circulation associated with persistence throughout the year. Persistence distribution, further-more, is found to be generally compatible with current theories suggesting that persistence is of local origin arising from the anomalous thermal state of the earth's surface. It is found that month-to-month temperature persistence is essentially independent of long-term temperature trends and of relationships between the temperatures of a given month in adjacent years. However, regions of month-to-month persistence are found to correspond broadly to areas of maximum secular temperature fluctuation. Furthermore, in central portions of winter, spring, and summer persistence regions, instances of warm and cold month-to-month persistence were to a large extent confined to warm and cold epochs, respectively. It is therefore postulated that the basic mechanisms responsible for secular temperature fluctuations and month-to-month temperature persistence are essentially the same.