Climate and Average Weather Year Round in De Aar South Africa

In De Aar, the summers are hot; the winters are short, cold, and windy; and it is dry and mostly clear year round. Over the course of the year, the temperature typically varies from 38°F to 89°F and is rarely below 31°F or above 96°F.

Based on the beach/pool score, the best time of year to visit De Aar for hot-weather activities is from early December to early March.

The hot season lasts for 3.6 months, from November 23 to March 11, with an average daily high temperature above 83°F. The hottest month of the year in De Aar is January, with an average high of 89°F and low of 63°F.

The cool season lasts for 2.8 months, from May 21 to August 15, with an average daily high temperature below 66°F. The coldest month of the year in De Aar is July, with an average low of 39°F and high of 62°F.

In De Aar, the average percentage of the sky covered by clouds experiences mild seasonal variation over the course of the year.

The clearer part of the year in De Aar begins around December 2 and lasts for 3.9 months, ending around March 29.

The clearest month of the year in De Aar is February, during which on average the sky is clear, mostly clear, or partly cloudy 84% of the time.

The cloudier part of the year begins around March 29 and lasts for 8.1 months, ending around December 2.

The cloudiest month of the year in De Aar is October, during which on average the sky is overcast or mostly cloudy 29% of the time.

A wet day is one with at least 0.04 inches of liquid or liquid-equivalent precipitation. The chance of wet days in De Aar varies throughout the year.

The wetter season lasts 5.0 months, from November 13 to April 14, with a greater than 12% chance of a given day being a wet day. The month with the most wet days in De Aar is February, with an average of 5.7 days with at least 0.04 inches of precipitation.

The drier season lasts 7.0 months, from April 14 to November 13. The month with the fewest wet days in De Aar is July, with an average of 1.0 days with at least 0.04 inches of precipitation.

Among wet days, we distinguish between those that experience rain alone, snow alone, or a mixture of the two. The month with the most days of rain alone in De Aar is February, with an average of 5.7 days. Based on this categorization, the most common form of precipitation throughout the year is rain alone, with a peak probability of 20% on February 17.

Rainfall

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. De Aar experiences some seasonal variation in monthly rainfall.

The rainy period of the year lasts for 7.5 months, from September 24 to May 8, with a sliding 31-day rainfall of at least 0.5 inches. The month with the most rain in De Aar is February, with an average rainfall of 1.4 inches.

The rainless period of the year lasts for 4.5 months, from May 8 to September 24. The month with the least rain in De Aar is July, with an average rainfall of 0.2 inches.

The length of the day in De Aar varies significantly over the course of the year. In 2024, the shortest day is June 20, with 10 hours, 10 minutes of daylight; the longest day is December 21, with 14 hours, 8 minutes of daylight.

The earliest sunrise is at 5:13 AM on December 3, and the latest sunrise is 2 hours, 8 minutes later at 7:22 AM on June 30. The earliest sunset is at 5:29 PM on June 10, and the latest sunset is 2 hours, 2 minutes later at 7:30 PM on January 9.

Daylight saving time (DST) is not observed in De Aar during 2024.

The figure below presents a compact representation of key lunar data for 2024. The horizontal axis is the day, the vertical axis is the hour of the day, and the colored areas indicate when the moon is above the horizon. The vertical gray bars (new Moons) and blue bars (full Moons) indicate key Moon phases.

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 De Aar, 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 1% of 1% throughout.

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 De Aar experiences mild seasonal variation over the course of the year.

The windier part of the year lasts for 6.1 months, from July 27 to February 2, with average wind speeds of more than 10.1 miles per hour. The windiest month of the year in De Aar is November, with an average hourly wind speed of 11.4 miles per hour.

The calmer time of year lasts for 5.8 months, from February 2 to July 27. The calmest month of the year in De Aar is April, with an average hourly wind speed of 8.8 miles per hour.

The predominant average hourly wind direction in De Aar varies throughout the year.

The wind is most often from the north for 4.1 months, from April 19 to August 21, with a peak percentage of 45% on July 3. The wind is most often from the west for 7.9 months, from August 21 to April 19, with a peak percentage of 37% on January 1.

To characterize how pleasant the weather is in De Aar throughout the year, we compute two travel scores.

The tourism score favors clear, rainless days with perceived temperatures between 65°F and 80°F. Based on this score, the best time of year to visit De Aar for general outdoor tourist activities is from early October to mid April, with a peak score in the third week of March.

The beach/pool score favors clear, rainless days with perceived temperatures between 75°F and 90°F. Based on this score, the best time of year to visit De Aar for hot-weather activities is from early December to early March, with a peak score in the second week of January.

Methodology

For each hour between 8:00 AM and 9:00 PM of each day in the analysis period (1980 to 2016), independent scores are computed for perceived temperature, cloud cover, and total precipitation. Those scores are combined into a single hourly composite score, which is then aggregated into days, averaged over all the years in the analysis period, and smoothed.

Our cloud cover score is 10 for fully clear skies, falling linearly to 9 for mostly clear skies, and to 1 for fully overcast skies.

Our precipitation score, which is based on the three-hour precipitation centered on the hour in question, is 10 for no precipitation, falling linearly to 9 for trace precipitation, and to 0 for 0.04 inches of precipitation or more.

Our tourism temperature score is 0 for perceived temperatures below 50°F, rising linearly to 9 for 65°F, to 10 for 75°F, falling linearly to 9 for 80°F, and to 1 for 90°F or hotter.

Our beach/pool temperature score is 0 for perceived temperatures below 65°F, rising linearly to 9 for 75°F, to 10 for 82°F, falling linearly to 9 for 90°F, and to 1 for 100°F or hotter.

Definitions of the growing season vary throughout the world, but for the purposes of this report, we define it as the longest continuous period of non-freezing temperatures (≥ 32°F) in the year (the calendar year in the Northern Hemisphere, or from July 1 until June 30 in the Southern Hemisphere).

The growing season in De Aar typically lasts for 9.9 months (300 days), from around August 14 to around June 11, rarely starting after September 8, or ending before May 17.

Growing degree days are a measure of yearly heat accumulation used to predict plant and animal development, and defined as the integral of warmth above a base temperature, discarding any excess above a maximum temperature. In this report, we use a base of 50°F and a cap of 86°F.

Based on growing degree days alone, the first spring blooms in De Aar should appear around July 25, only rarely appearing before July 19 or after July 31.

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 3.2 months, from November 3 to February 10, with an average daily incident shortwave energy per square meter above 7.9 kWh. The brightest month of the year in De Aar is December, with an average of 8.9 kWh.

The darker period of the year lasts for 3.4 months, from April 28 to August 10, with an average daily incident shortwave energy per square meter below 4.6 kWh. The darkest month of the year in De Aar is June, with an average of 3.6 kWh.

For the purposes of this report, the geographical coordinates of De Aar are -30.650 deg latitude, 24.012 deg longitude, and 4,091 ft elevation.

The topography within 2 miles of De Aar contains only modest variations in elevation, with a maximum elevation change of 417 feet and an average elevation above sea level of 4,115 feet. Within 10 miles contains only modest variations in elevation (1,135 feet). Within 50 miles contains very significant variations in elevation (3,028 feet).

The area within 2 miles of De Aar is covered by shrubs (43%), artificial surfaces (39%), and bare soil (18%), within 10 miles by shrubs (92%), and within 50 miles by shrubs (96%).