Average Weather in Cape Town South Africa
In Cape Town, the summers are warm, dry, and mostly clear; the winters are long, cool, wet, and partly cloudy; and it is windy year round. Over the course of the year, the temperature typically varies from 48°F to 76°F and is rarely below 41°F or above 84°F.
The warm season lasts for 3.7 months, from December 7 to March 28, with an average daily high temperature above 73°F. The hottest day of the year is January 27, with an average high of 76°F and low of 63°F.
The cool season lasts for 3.7 months, from May 28 to September 19, with an average daily high temperature below 65°F. The coldest day of the year is July 11, with an average low of 48°F and high of 62°F.
Average High and Low Temperature
The figure below shows you a compact characterization of the entire year of hourly average temperatures. The horizontal axis is the day of the year, the vertical axis is the hour of the day, and the color is the average temperature for that hour and day.
Average Hourly Temperature
In Cape Town, the average percentage of the sky covered by clouds experiences significant seasonal variation over the course of the year.
The clearer part of the year in Cape Town begins around November 24 and lasts for 4.2 months, ending around April 1. On February 10, the clearest day of the year, the sky is clear, mostly clear, or partly cloudy 89% of the time, and overcast or mostly cloudy 11% of the time.
The cloudier part of the year begins around April 1 and lasts for 7.8 months, ending around November 24. On May 19, the cloudiest day of the year, the sky is overcast or mostly cloudy 44% of the time, and clear, mostly clear, or partly cloudy 56% of the time.
Cloud Cover Categories
A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days in Cape Town varies throughout the year.
The wetter season lasts 5.4 months, from April 19 to September 30, with a greater than 16% chance of a given day being a wet day. The chance of a wet day peaks at 27% on June 15.
The drier season lasts 6.6 months, from September 30 to April 19. The smallest chance of a wet day is 4% on February 11.
Among wet days, we distinguish between those that experience rain alone, snow alone, or a mixture of the two. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 27% on June 15.
Daily Chance of Precipitation
To show variation within the months and not just the monthly totals, we show the rainfall accumulated over a sliding 31-day period centered around each day of the year. Cape Town experiences significant seasonal variation in monthly rainfall.
The rainy period of the year lasts for 8.8 months, from March 10 to December 3, with a sliding 31-day rainfall of at least 0.5 inches. The most rain falls during the 31 days centered around June 25, with an average total accumulation of 3.0 inches.
The rainless period of the year lasts for 3.2 months, from December 3 to March 10. The least rain falls around February 20, with an average total accumulation of 0.4 inches.
Average Monthly Rainfall
The length of the day in Cape Town varies significantly over the course of the year. In 2017, the shortest day is June 21, with 9 hours, 54 minutes of daylight; the longest day is December 21, with 14 hours, 25 minutes of daylight.
Hours of Daylight and Twilight
The earliest sunrise is at 5:28 AM on December 5, and the latest sunrise is 2 hours, 24 minutes later at 7:52 AM on June 30. The earliest sunset is at 5:43 PM on June 11, and the latest sunset is 2 hours, 18 minutes later at 8:01 PM on January 7.
Daylight saving time (DST) is not observed in Cape Town during 2017.
Sunrise & Sunset with Twilight
We base the humidity comfort level on the dew point, as it determines whether perspiration will evaporate from the skin, thereby cooling the body. Lower dew points feel drier and higher dew points feel more humid. Unlike temperature, which typically varies significantly between night and day, dew point tends to change more slowly, so while the temperature may drop at night, a muggy day is typically followed by a muggy night.
The perceived humidity level in Cape Town, as measured by the percentage of time in which the humidity comfort level is muggy, oppressive, or miserable, does not vary significantly over the course of the year, staying within 4% of 4% throughout.
Humidity Comfort Levels
This section discusses the wide-area hourly average wind vector (speed and direction) at 10 meters above the ground. The wind experienced at any given location is highly dependent on local topography and other factors, and instantaneous wind speed and direction vary more widely than hourly averages.
The average hourly wind speed in Cape Town experiences mild seasonal variation over the course of the year.
The windier part of the year lasts for 5.4 months, from October 8 to March 19, with average wind speeds of more than 6.6 miles per hour. The windiest day of the year is January 22, with an average hourly wind speed of 7.5 miles per hour.
The calmer time of year lasts for 6.6 months, from March 19 to October 8. The calmest day of the year is May 3, with an average hourly wind speed of 5.7 miles per hour.
Average Wind Speed
The predominant average hourly wind direction in Cape Town varies throughout the year.
The wind is most often from the north for 2.9 months, from May 13 to August 10, with a peak percentage of 35% on June 27. The wind is most often from the west for 2.6 weeks, from August 10 to August 28, with a peak percentage of 31% on August 27. The wind is most often from the south for 8.5 months, from August 28 to May 13, with a peak percentage of 65% on January 1.
Cape Town is located near a large body of water (e.g., ocean, sea, or large lake). This section reports on the wide-area average surface temperature of that water.
The average water temperature experiences some seasonal variation over the course of the year.
The time of year with warmer water lasts for 2.5 months, from December 24 to March 10, with an average temperature above 65°F. The day of the year with the warmest water is February 4, with an average temperature of 66°F.
The time of year with cooler water lasts for 4.7 months, from June 5 to October 28, with an average temperature below 60°F. The day of the year with the coolest water is August 4, with an average temperature of 59°F.
Average Water Temperature
This section discusses the total daily incident shortwave solar energy reaching the surface of the ground over a wide area, taking full account of seasonal variations in the length of the day, the elevation of the Sun above the horizon, and absorption by clouds and other atmospheric constituents. Shortwave radiation includes visible light and ultraviolet radiation.
The average daily incident shortwave solar energy experiences extreme seasonal variation over the course of the year.
The brighter period of the year lasts for 3.5 months, from November 7 to February 21, with an average daily incident shortwave energy per square meter above 7.4 kWh. The brightest day of the year is January 3, with an average of 8.7 kWh.
The darker period of the year lasts for 3.7 months, from April 29 to August 20, with an average daily incident shortwave energy per square meter below 3.7 kWh. The darkest day of the year is June 24, with an average of 2.5 kWh.
Average Daily Incident Shortwave Solar Energy
For the purposes of this report, the geographical coordinates of Cape Town are -33.926 deg latitude, 18.423 deg longitude, and 82 ft elevation.
The topography within 2 miles of Cape Town contains large variations in elevation, with a maximum elevation change of 2,405 feet and an average elevation above sea level of 318 feet. Within 10 miles contains large variations in elevation (3,596 feet). Within 50 miles also contains extreme variations in elevation (6,568 feet).
The area within 2 miles of Cape Town is covered by artificial surfaces (69%) and shrubs (20%), within 10 miles by water (46%) and artificial surfaces (39%), and within 50 miles by water (62%) and cropland (22%).
This report illustrates the typical weather in Cape Town, based on a statistical analysis of historical hourly weather reports and model reconstructions from January 1, 1980 to December 31, 2016.
Temperature and Dew Point
There are 2 weather stations near enough to contribute to our estimation of the temperature and dew point in Cape Town.
For each station, the records are corrected for the elevation difference between that station and Cape Town according to the International Standard Atmosphere , and by the relative change present in the MERRA-2 satellite-era reanalysis between the two locations.
The estimated value at Cape Town is computed as the weighted average of the individual contributions from each station, with weights proportional to the inverse of the distance between Cape Town and a given station.
All data relating to the Sun's position (e.g., sunrise and sunset) are computed using astronomical formulas from the book, Astronomical Tables of the Sun, Moon and Planets , by Jean Meeus.
All other weather data, including cloud cover, precipitation, wind speed and direction, and solar flux, come from NASA's MERRA-2 Modern-Era Retrospective Analysis . This reanalysis combines a variety of wide-area measurements in a state-of-the-art global meteorological model to reconstruct the hourly history of weather throughout the world on a 50-kilometer grid.
Land Use data comes from the Global Land Cover SHARE database , published by the Food and Agriculture Organization of the United Nations.
Elevation data comes from the Shuttle Radar Topography Mission (SRTM) , published by NASA's Jet Propulsion Laboratory.
Names, locations, and time zones of places and some airports come from the GeoNames Geographical Database .
Time zones for aiports and weather stations are provided by AskGeo.com .
Maps are © Esri, with data from National Geographic, Esri, DeLorme, NAVTEQ, UNEP-WCMC, USGS, NASA, ESA, METI, NRCAN, GEBCO, NOAA, and iPC.