Because of the possibility of long-term desiccation and resulting ecological problems in southern Africa, analyses of spatial variability and temporal periodicity of rainfall are of great importance. Rainfall in the Etosha National Park and surrounding areas in northern Namibia decreases from east to west and rainfall isohyets show a nearly meridional arrangement. Keyword: 18-year oscillation, Agriculture, Climate, Equatorial moist air masses, National economy, Periodicities of rainfall and Wind direction.