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Weather & Climate in Koster, South Africa
Temperature, precipitation, air quality, natural hazards, and monthly weather data.
Koster enjoys a temperate climate with an average annual temperature of 61°F (16°C). Winters average 70°F in January while summers reach 49°F in July / relatively mild seasonal variation. The area gets 288 sunny days per year, well above the U.S. average of 205 / making it one of the sunnier locations in the country. Annual precipitation totals 26.4 inches (drier than the 38-inch national average). The city sits at an elevation of 5,315 feet.
Temperature
70°F Jan (21°C)
49°F Jul (9°C)
| Annual Average | 61.4°F |
| 14% above US avg | |
| January Average | 70°F (21°C) |
| July Average | 49°F (9°C) |
| Sunny Days | 288 days/yr |
Geography
| Elevation | 5,315 ft (1,620 m) |
| Area | 1,639.4 sq mi (4,245.9 km²) |
| Population Density | 14/sq mi |
| Coordinates | -25.8630°N, 26.8976°W |
| Timezone | Africa/Johannesburg |
Precipitation & Snow
Air Quality
Earthquake History
963 earthquakes (M2.5+) recorded within 150 km since 1990. Strongest on record: M5.4.
| Aug 5, 2014 | 3 km ESE of Orkney, South Africa | M5.4 | 127 km | 5 km |
| Apr 3, 2017 | 7 km SSE of Stilfontein, South Africa | M5.2 | 117 km | 5 km |
| Feb 10, 1997 | 5 km SSE of Orkney, South Africa | M5.2 | 130 km | 5 km |
| Nov 3, 1991 | 5 km SE of Klerksdorp, South Africa | M5.1 | 116 km | 5 km |
| Dec 1, 1991 | 2 km S of Klerksdorp, South Africa | M5.0 | 115 km | 10 km |
| Mar 16, 2009 | 8 km ENE of Orkney, South Africa | M5.0 | 122 km | 2 km |
| May 27, 2002 | 4 km ENE of Orkney, South Africa | M5.0 | 124 km | 5 km |
| Jul 21, 1997 | 4 km W of Klerksdorp, South Africa | M5.0 | 114 km | 5 km |
| Mar 9, 2005 | 7 km SSE of Stilfontein, South Africa | M5.0 | 117 km | 5 km |
| Jun 14, 2010 | 8 km NNW of Fochville, South Africa | M5.0 | 84 km | 2 km |
| Dec 11, 1997 | 7 km SSW of Klerksdorp, South Africa | M4.9 | 119 km | 5 km |
| Dec 5, 1998 | 9 km NNE of Fochville, South Africa | M4.9 | 87 km | 10 km |
| Aug 6, 2000 | 8 km SSW of Westonaria, South Africa | M4.9 | 91 km | 5 km |
| Jun 11, 2023 | Gauteng, South Africa | M4.9 | 136 km | 5 km |
| Sep 6, 2004 | 17 km WNW of Klerksdorp, South Africa | M4.9 | 109 km | 10 km |
| Nov 25, 1995 | South Africa | M4.9 | 119 km | 13 km |
| Jul 31, 2001 | 8 km SW of Klerksdorp, South Africa | M4.9 | 120 km | 5 km |
| Feb 17, 2005 | 13 km WSW of Klerksdorp, South Africa | M4.9 | 122 km | 5 km |
| Mar 7, 1992 | 14 km W of Fochville, South Africa | M4.9 | 85 km | 10 km |
| Jun 15, 2014 | 8 km E of Orkney, South Africa | M4.9 | 126 km | 5 km |
Source: USGS Earthquake Catalog (M2.5+, 1990-2025). Sorted by magnitude.
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 70°F (21°C) | 5.0 in | Warmest, Wettest |
| February | 69°F (20°C) | 3.9 in | |
| March | 66°F (19°C) | 3.6 in | |
| April | 61°F (16°C) | 1.9 in | |
| May | 55°F (13°C) | 0.6 in | |
| June | 50°F (10°C) | 0.2 in | |
| July | 49°F (9°C) | 0.2 in | Coldest, Driest |
| August | 54°F (12°C) | 0.3 in | |
| September | 61°F (16°C) | 0.9 in | |
| October | 66°F (19°C) | 2.2 in | |
| November | 68°F (20°C) | 3.3 in | |
| December | 69°F (21°C) | 4.4 in |
Koster has a seasonal temperature swing of 21°F / from 49°F in July to 70°F in January. Total annual precipitation is 26.4 inches, with January being the wettest month (5.0") and July the driest (0.2").