South Africa enjoys a generally warm, temperate climate. Most of the country experiences light rainfall and long hours of sunshine.

Rainfall is typically unpredictable. Prolonged droughts often end with severe floods. Only 31 percent of the country, including the Eastern Low Veld and the Drakensberg, has an annual rainfall of more than 600 mm (25 in); 48 percent receives from 200 mm to 600 mm (8 to 24 in), including much of the High Veld, where rainfall diminishes rapidly from east to west; 21 percent, in the west, is arid, with less than 200 mm (8 in). Rain falls primarily in summer between October and April. In the drier regions of the plateaus the amount of rainfall and the beginning of the rainy season vary greatly from year to year. The extreme southwest has a Mediterranean climate with westerly winds from the Atlantic bringing winter rainfall mostly between June and September.

Since most of South Africa is at a high elevation, temperatures tend to be lower than those of other regions at similar latitudes. There is a striking difference between temperatures on the east and west coasts. The east coast is influenced by the warm Agulhas Current and the west coast by the cold Benguela Current. This results in a temperature difference of 6°C (11°F) in the mean annual temperatures of Durban on the east coast and Port Nolloth on the west coast, which are at similar latitudes. Average temperature ranges in January are 21° to 27°C (69° to 81°F) in Durban, 14° to 26°C (58° to 78°F) in Johannesburg, and 16° to 26°C (60° to 79°F) in Cape Town. In July the temperature ranges are 11° to 22°C (52° to 72°F) in Durban, 4° to 17°C (39° to 63°F) in Johannesburg, and 7° to 17°C (45° to 63°F) in Cape Town. Snow is rare except in the higher parts of the Drakensberg, but winter frosts occur on the higher parts of the plateau.