Drought -- National Drought Mitigation Center


Date of this Version



Published in Drought: A Global Assessment, Vol. II, edited by Donald A. Wilhite, chap. 39, pp. 149–157 (London: Routledge, 2000).

Note: This chapter is reprinted from Journal of the American Water Resources Association, vol. 33, no. 5, October 1977, pp. 961–68.


Copyright © 2000 Donald A. Wilhite for the selection and editorial matter; individual chapters, the contributors.


Drought is a normal, recurrent feature of the climate of virtually all portions of the United States. Because of the country’s size and the wide range of climatic regimes, it is rare for drought not to exist somewhere in the country each year. The most recent series of drought years that has plagued the country since 1986 has extended almost uninterrupted to the present. During this time, drought has affected all or a portion of nearly all states; in some instances, states were affected for six or seven consecutive years. The percent area of the contiguous United States, according to the Palmer Drought Severity Index (Palmer 1965), that has been in severe and extreme drought (i.e., ≤–3.0) from 1986 to 1995 is shown in figure 39.1. During 1988, the most severe drought year, nearly 40 percent of the nation was in severe to extreme drought. In 1996, the drought in the Southwest and southern Great Plains states affected approximately 20 percent of the nation.