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Marked interannual fluctuations in rainfall are a fundamental aspect of southern African climate. This study uses dry spell frequency (DSF) to assess spatial and temporal patterns in the consistency of rainfall during the mid-summer (DJF) season and their relationships to interannual drought occurrences in southern Africa. The Climate Prediction Center Merged Analysis of Precipitation (CMAP) pentad data are used to identify dry spells, which are defined here as a pentad with mean daily rainfall less than 1 mm. It was found that DSFs over most of southern Africa are highest (lowest) during El Niño (La Niña) events and that their occurrence is associated with shifts in the location of the tropical-temperate-trough (TTT) systems that are the dominant rain-producing systems over much of southern Africa. The latter are tropical-extratropical cloudbands that link a tropical low over low latitude southern Africa with a westerly …