Cape Town has a warm Mediterranean climate ,
with mild, moderately wet winters and dry, warm summers. Winter, which lasts from the beginning of June to the end of August, may see large cold fronts entering for limited periods from the Atlantic Ocean with significant precipitation and strong north-westerly winds. Winter months in the city average a maximum of 18 °C (64 °F) and minimum of 8.5 °C (47 °F)
Total annual rainfall in the city averages 515 millimetres (20.3 in) although in the Southern Suburbs, close to the mountains, rainfall is significantly higher and averages closer to 1,000 millimetres (39.4 in). Summer, which lasts from December to March, is warm and dry with an average maximum of 26 °C (79 °F) and minimum of 16 °C (61 °F). The region can get uncomfortably hot when the Berg Wind, meaning “mountain wind”, blows from the Karoo interior. Spring and summer generally feature a strong wind from the south-east, known locally as the south-easter or the Cape Doctor, so called because it blows air pollution away. This wind is caused by a persistent high-pressure system over the South Atlantic to the west of Cape Town, known as the South Atlantic High, which shifts latitude seasonally, following the sun, and influencing the strength of the fronts and their northward reach. Cape Town receives about 3,100 hours of sunshine per year.
Water temperatures range greatly, between 10 °C (50 °F) on the Atlantic Seaboard, to over 22 °C (72 °F) in False Bay. Average annual ocean surface temperatures are between 13 °C (55 °F) on the Atlantic Seaboard (similar to Californian waters, such as San Francisco or Big Sur), and 17 °C (63 °F) in False Bay (similar to Northern Mediterranean temperatures, such as Nice or Monte Carlo).
Unlike other parts of the country the city does not have many thunderstorms, and most of those that do occur, happen around October to December and March to April.