This report describes the typical weather at the Cape Town International Airport (Cape Town, South Africa) weather station over the course of an average year. It is based on the historical records from 1994 to 2012. Earlier records are either unavailable or unreliable.
Cape Town has a mediterranean climate with dry warm summers and mild winters. The area within 25 mi of this station is covered by oceans and seas (40%), grasslands (33%), croplands (17%), built-up areas (6%), and forests (5%).
Over the course of a year, the temperature typically varies from 45°F to 80°F and is rarely below 39°F or above 88°F.
The warm season lasts from December 9 to March 27 with an average daily high temperature above 77°F. The hottest day of the year is February 15, with an average high of 80°F and low of 62°F.
The cold season lasts from May 26 to September 14 with an average daily high temperature below 66°F. The coldest day of the year is July 5, with an average low of 45°F and high of 64°F.
The length of the day varies significantly over the course of the year. The shortest day is June 20 with 9:54 hours of daylight; the longest day is December 21 with 14:25 hours of daylight.
The earliest sunrise is at 5:27am on December 7 and the latest sunset is at 8:01pm on January 8. The latest sunrise is at 7:52am on June 28 and the earliest sunset is at 5:43pm on June 13.
Daylight savings time (DST) is not observed in 2012.
The median cloud cover ranges from 26% (mostly clear) to 54% (partly cloudy). The sky is cloudiest on August 28 and clearest on February 14. The clearer part of the year begins around October 9. The cloudier part of the year begins around April 23.
On February 14, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 71% of the time, and overcast or mostly cloudy 15% of the time.
On August 28, the cloudiest day of the year, the sky is overcast, mostly cloudy, or partly cloudy 48% of the time, and clear or mostly clear 40% of the time.
The probability that precipitation will be observed at this location varies throughout the year. Precipitation is most likely around June 17, occurring in 45% of days. Precipitation is least likely around February 8, occurring in 15% of days.
Over the entire year, the most common forms of precipitation are moderate rain and light rain.
Moderate rain is the most severe precipitation observed during 49% of those days with precipitation. It is most likely around July 7, when it is observed during 26% of all days.
Light rain is the most severe precipitation observed during 39% of those days with precipitation. It is most likely around June 10, when it is observed during 17% of all days.
During the warm season, which lasts from December 9 to March 27, there is a 17% average chance that precipitation will be observed at some point during a given day. When precipitation does occur it is most often in the form of light rain (43% of days with precipitation have at worst light rain), moderate rain (39%), drizzle (12%), and thunderstorms (7%).
During the cold season, which lasts from May 26 to September 14, there is a 42% average chance that precipitation will be observed at some point during a given day. When precipitation does occur it is most often in the form of moderate rain (56% of days with precipitation have at worst moderate rain) and light rain (36%).
Either snow is exceptionally unlikely to fall at any time during the year at this location or this station does not reliably report precipitation types.
The relative humidity typically ranges from 44% (comfortable) to 97% (very humid) over the course of the year, rarely dropping below 29% (dry) and reaching as high as 100% (very humid).
The air is driest around December 3, at which time the relative humidity drops below 51% (mildly humid) three days out of four; it is most humid around July 12, exceeding 95% (very humid) three days out of four.
Dew point is often a better measure of how comfortable a person will find the weather than relative humidity because it more directly relates to whether perspiration will evaporate from the skin, thereby cooling the body. Lower dew points feel drier and higher dew points feel more humid.
Over the course of a year, the dew point typically varies from 40°F (dry) to 62°F (mildy humid) and is rarely below 34°F (dry) or above 66°F (muggy).
The time of the year between January 1 and December 31 is the most comfortable, with dew points that are neither too dry nor too muggy.
Over the course of the year typical wind speeds vary from 1 mph to 24 mph (light air to fresh breeze), rarely exceeding 31 mph (high wind).
The highest average wind speed of 15 mph (moderate breeze) occurs around January 18, at which time the average daily maximum wind speed is 24 mph (fresh breeze).
The lowest average wind speed of 8 mph (gentle breeze) occurs around July 5, at which time the average daily maximum wind speed is 14 mph (moderate breeze).