The following climate description is from Microsost's Encarta website :

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 Celsius degrees (11 Fahrenheit degrees) 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.

SOURCE:
"South Africa," Microsoft® Encarta® Online Encyclopedia 2000
http://encarta.msn.com © 1997-2001 Microsoft Corporation. All rights reserved.

Visitors to Cape Town, take note that the climate statistics are from the International Airport, about 15km (9miles), from the city center. Cape Town is very unique in the world, since owing to the geography of the area, areas around Cape Town may experience VASTLY different weather at the same time. Sometimes in summer, the south east winds can be roaring up to 80km/h (50mph) at Cape Point where the temperature will be 20°C (70°F), yet in the city center it may be dead calm with a temperature of 40°C (105°F). The mountains of the Peninsula, which run N-S, generally protect the Atlantic coastline beaches from the SE winds in summer, making them an ideal escape.

In winter, the very same mountains of the Peninsula cause very high rainfall totals on the lee side. Areas like Newlands receive excessive rainfall amounts at times, with annual rainfall totals around 2000mm (80"), making it the wettest suburb in South Africa. Keep in mind that the airport is only about 15km (9m) away where the annual rainfall is only ~530mm (~21"). Fierce gales often batter the Peninsula from May to AUG with strong NW winds and heavy rains.

The airport, where all official "Cape Town" weather data is measured lies on the exposed Cape Flats, and gives a general idea of what most of the metropolitain areas experience. We hope to add further data for areas around Cape Town in the future.

Data exists for the 16 MetroCast forecast cities. Data is from the South African Weather Service.

Please read our disclaimer before using any of this data. If you use this data, you must accredit the SAWS (South African Weather Service) and 1stweather as sources!

The climate data format is as follows :

• 10 warmest/coldest years : Average Maximum temperature (Monthly and annual)
  
• 10 warmest/coldest years : Average Minimum temperature (Monthly and annual)
  
• 10 warmest/coldest years : Average temperature (Monthly and annual)
  
• 10 wettest/driest years : Rainfall (Monthly and annual)
  
• Climate averages and absolutes