Abnormalities in the performance of the Indian summer monsoon (June to September) rainfall, which provides 75-90 per cent of annual rainfall, have been studied during the period 1871 to 1984 over different meteorological subdivisions into which the country has been divided. Long homogeneous monsoon rainfall series of 29 subdivisions, prepared on the basis of a constant 306 rain gauges, have been tabulated for the users in view of their great importance. The criterion adopted in identification of droughtlflood over a subdivision is the percentage of rainfall departures from normal, as officially used in the India Meteorological Department.The worst drought years were