The rainfall climate of South Africa is one of great variability. Seasonal rainfall percentage deviations since 1960 demonstrate wide fluctuations about the long-term average and it is in this context that large rainfall deficits must be assessed. Between July of 1960 and June of 2004, there have been 8 summer-rainfall seasons where rainfall for the entire summer-rainfall area has been less than 80% of normal. A deficit of 25% is normally regarded as a severe meteorological drought but it can be safely assumed that a shortfall of 20% from normal rainfall will cause crop and water shortfalls in many regions accompanied by social and economic hardship.