Mean rainfall for the periods 1950-1959, 1960-1969, 1970-1979, and 1980-1989 (panels a through d respectively). Rainfall is expressed as a percentage departure from the long-term mean (i.e., the mean for the entire length of record, commencing in 1901 or as soon thereafter as rainfall observations begin). Station data are averaged over 1° squares to facilitate presentation. Shading highlights regions with positive anomalies. (The 1970-1979 map is reprinted from Nicholson, 1994, with permission of Arnold, of the Hodder Headline Group; the 1980-1989 map is reprinted from Nicholson, 1993, with permission of the American Meteorological Society.)

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