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Average Weather in August in Cape Town South Africa

In Cape Town, the month of August is characterized by essentially constant daily high temperatures, with daily highs around 63°F throughout the month, rarely exceeding 72°F or dropping below 57°F.

Daily low temperatures increase by 2°F, from 48°F to 50°F, rarely falling below 41°F or exceeding 55°F.

For reference, on January 27, the hottest day of the year, temperatures in Cape Town typically range from 63°F to 76°F, while on July 11, the coldest day of the year, they range from 48°F to 62°F.

Average High and Low Temperature in August

The daily average high (red line) and low (blue line) temperature, with 25th to 75th and 10th to 90th percentile bands. The thin dotted lines are the corresponding average perceived temperatures.

The figure below shows you a compact characterization of the hourly average temperatures for the quarter of the year centered on August. The horizontal axis is the day, 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 August

Average Hourly Temperature in August in Cape Town12 AM4 AM8 AM12 PM4 PM8 PM12 AM181522291122334455667788991010111112121313141415151616171718181919202021212222232324242525262627272828292930303131JulJulSepSepcoldcoldcoolcoolcomfortablecomfortable
The average hourly temperature, color coded into bands: frigid < 15°F < freezing < 32°F < chilly < 45°F < cold < 55°F < cool < 65°F < comfortable < 75°F < warm < 85°F < hot < 95°F < sweltering. The shaded overlays indicate night and civil twilight.

Clouds

The month of August in Cape Town experiences essentially constant cloud cover, with the percentage of time that the sky is overcast or mostly cloudy remaining about 35% throughout the month. The lowest chance of overcast or mostly cloudy conditions is 32% on August 11.

The clearest day of the month is August 11, with clear, mostly clear, or partly cloudy conditions 68% of the time.

For reference, on May 19, the cloudiest day of the year, the chance of overcast or mostly cloudy conditions is 44%, while on February 10, the clearest day of the year, the chance of clear, mostly clear, or partly cloudy skies is 89%.

Cloud Cover in August

The percentage of time spent in each cloud cover band, categorized by the percentage of the sky covered by clouds: clear < 20% < mostly clear < 40% < partly cloudy < 60% < mostly cloudy < 80% < overcast.

Precipitation

A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. In Cape Town, the chance of a wet day over the course of August is gradually decreasing, starting the month at 24% and ending it at 20%.

For reference, the year's highest daily chance of a wet day is 27% on June 15, and its lowest chance is 4% on February 13.

Probability of Precipitation in August

The percentage of days in which various types of precipitation are observed, excluding trace quantities: rain alone, snow alone, and mixed (both rain and snow fell in the same day).

Rainfall

To show variation within the month and not just the monthly total, we show the rainfall accumulated over a sliding 31-day period centered around each day.

The average sliding 31-day rainfall during August in Cape Town is decreasing, starting the month at 2.4 inches, when it rarely exceeds 4.6 inches or falls below 0.8 inches, and ending the month at 1.9 inches, when it rarely exceeds 3.5 inches or falls below 0.4 inches.

Average Monthly Rainfall in August

The average rainfall (solid line) accumulated over the course of a sliding 31-day period centered on the day in question, with 25th to 75th and 10th to 90th percentile bands. The thin dotted line is the corresponding average liquid-equivalent snowfall.

Sun

Over the course of August in Cape Town, the length of the day is increasing. From the start to the end of the month, the length of the day increases by 54 minutes, implying an average daily increase of 1 minute, 47 seconds, and weekly increase of 12 minutes, 31 seconds.

The shortest day of the month is August 1, with 10 hours, 28 minutes of daylight and the longest day is August 31, with 11 hours, 22 minutes of daylight.

Hours of Daylight and Twilight in August

The number of hours during which the Sun is visible (black line). From bottom (most yellow) to top (most gray), the color bands indicate: full daylight, twilight (civil, nautical, and astronomical), and full night.

The latest sunrise of the month in Cape Town is 7:38 AM on August 1 and the earliest sunrise is 33 minutes earlier at 7:05 AM on August 31.

The earliest sunset is 6:06 PM on August 1 and the latest sunset is 21 minutes later at 6:27 PM on August 31.

Daylight saving time is not observed in Cape Town during 2017.

For reference, on December 21, the longest day of the year, the Sun rises at 5:31 AM and sets 14 hours, 25 minutes later, at 7:57 PM, while on June 21, the shortest day of the year, it rises at 7:51 AM and sets 9 hours, 54 minutes later, at 5:44 PM.

Sunrise & Sunset with Twilight in August

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

Humidity

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 chance that a given day will be muggy in Cape Town is essentially constant during August, remaining around 0% throughout.

For reference, on February 11, the muggiest day of the year, there are muggy conditions 9% of the time, while on May 25, the leasy muggy day of the year, there are muggy conditions 0% of the time.

Humidity Comfort Levels in August

The percentage of time spent at various humidity comfort levels, categorized by dew point: dry < 55°F < comfortable < 60°F < humid < 65°F < muggy < 70°F < oppressive < 75°F < miserable.

Wind

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 is essentially constant during August, remaining within 0.1 miles per hour of 6.2 miles per hour throughout.

For reference, on January 22, the windiest day of the year, the daily average wind speed is 7.5 miles per hour, while on May 3, the calmest day of the year, the daily average wind speed is 5.7 miles per hour.

Average Wind Speed in August

The average of mean hourly wind speeds (dark gray line), with 25th to 75th and 10th to 90th percentile bands.
The wind direction in Cape Town during August is predominantly out of the calm from August 1 to August 10, the calm from August 10 to August 28, and the calm from August 28 to August 31

Wind Direction in August

Wind Direction in August in Cape TownNNWWSS0%20%40%60%80%100%181522291122334455667788991010111112121313141415151616171718181919202021212222232324242525262627272828292930303131JulJulSepSepwestwestsouthsoutheasteastnorthnorth
The percentage of hours in which the mean wind direction is from each of the four cardinal wind directions (north, east, south, and west), excluding hours in which the mean wind speed is less than 1 mph. The lightly tinted areas at the boundaries are the percentage of hours spent in the implied intermediate directions (northeast, southeast, southwest, and northwest).

Water Temperature

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 surface water temperature in Cape Town is essentially constant during August, remaining around 59°F throughout.

The lowest average surface water temperature during August is 59°F on August 6.

Average Water Temperature in August

Average Water Temperature in August in Cape Town56.5°F57.0°F57.5°F58.0°F58.5°F59.0°F59.5°F60.0°F60.5°F61.0°F61.5°F181522291122334455667788991010111112121313141415151616171718181919202021212222232324242525262627272828292930303131JulJulSepSepAug 659°FAug 659°FAug 3159°FAug 3159°FAug 2159°FAug 2159°F
The daily average water temperature (purple line), with 25th to 75th and 10th to 90th percentile bands.

Solar Energy

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 in Cape Town is increasing during August, rising by 1.1 kWh, from 3.1 kWh to 4.2 kWh, over the course of the month.

Average Daily Incident Shortwave Solar Energy in August

The average daily shortwave solar energy reaching the ground per square meter (orange line), with 25th to 75th and 10th to 90th percentile bands.

Topography

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%).

Data Sources

This report illustrates the typical weather in Cape Town year round, 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.

The stations contributing to this reconstruction are: Cape Town International Airport (94%, 17 kilometers, east) and AFB Langebaanweg (6%, 109 kilometers, north).

Other Data

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.