Average Weather For Cape Town, South Africa

Location

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%).

Temperature

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.

Daily High and Low Temperature

The daily average low (blue) and high (red) temperature with percentile bands (inner band from 25th to 75th percentile, outer band from 10th to 90th percentile).

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.

Fraction of Time Spent in Various Temperature Bands

The average fraction of time spent in various temperature bands: frigid (below 15°F), freezing (15°F to 32°F), cold (32°F to 50°F), cool (50°F to 65°F), comfortable (65°F to 75°F), warm (75°F to 85°F), hot (85°F to 100°F) and sweltering (above 100°F).

Sun

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.

Daily Hours of Daylight and Twilight

The number of hours during which the Sun is visible (black line), with various degrees of daylight, twilight, and night, indicated by the color bands. From bottom (most yellow) to top (most gray): full daylight, solar twilight (Sun is visible but less than 6° from the horizon), civil twilight (Sun is not visible but is less than 6° below the horizon), nautical twilight (Sun is between 6° and 12° below the horizon), astronomical twilight (Sun is between 12° and 18° below the horizon), and full night.

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.

Daily Sunrise & Sunset with Twilight

The solar day over the course of the year 2012 . From bottom to top, the black lines are the previous solar midnight, sunrise, solar noon, sunset, and the next solar midnight. The day, twilights (solar, civil, nautical, and astronomical), and night are indicated by the color bands from yellow to gray.

Clouds

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.

Median Cloud Cover

The median daily cloud cover (black line) with percentile bands (inner band from 40th to 60th percentile, outer band from 25th to 75th percentile).

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.

Cloud Cover Types

The fraction of time spent in each of the five sky cover categories. From top (most blue) to bottom (most gray), the categories are clear, mostly clear, partly cloudy, mostly cloudy, and overcast. Pink indicates missing data. Outside of the United States clear skies are often reported ambiguously, leading them to be lumped in with the missing data.

Precipitation

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.

Probability of Precipitation at Some Point in the Day

The fraction of days in which various types of precipitation are observed. If more than one type of precipitation is reported in a given day, the more severe precipitation is counted. For example, if light rain is observed in the same day as a thunderstorm, that day counts towards the thunderstorm totals. The order of severity is from the top down in this graph, with the most severe at the bottom.

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.

Types of Precipitation Throughout the Year

Relative frequency of various types of precipitation over the course of a typical year.

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%).

Warm Season Precipitation

Cold Season Precipitation

Relative frequency of various types of precipitation during the warm and cold seasons respectively.

Snow

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.

Humidity

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.

Relative Humidity

The average daily high (blue) and low (brown) relative humidity with percentile bands (inner bands from 25th to 75th percentile, outer bands from 10th to 90th percentile).

Dew Point

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.

Dew Point

The daily average low (blue) and high (red) dew point with percentile bands (inner band from 25th to 75th percentile, outer band from 10th to 90th percentile).

Wind

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).

Wind Speed

The average daily minimum (red), maximum (green), and average (black) wind speed with percentile bands (inner band from 25th to 75th percentile, outer band from 10th to 90th percentile).
The wind is most often out of the south (32% of the time), north west (14% of the time), north (13% of the time), and south west (12% of the time). The wind is least often out of the east (2% of the time), north east (5% of the time), and west (5% of the time).

Wind Directions Over the Entire Year

The fraction of time spent with the wind blowing from the various directions over the entire year. Values do not sum to 100% because the wind direction is undefined when the wind speed is zero.

Fraction of Time Spent with Various Wind Directions

The fraction of time spent with the wind blowing from the various directions on a daily basis. Stacked values do not always sum to 100% because the wind direction is undefined when the wind speed is zero.