Climate averages 1991–2020
Johannesburg weather
in August.
A mild, very dry month: the 9th warmest and the 3rd driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
August is a mild month in Johannesburg: daytime highs average 19.4°C and nights cool to about 4.9°C. By daytime temperature it is the 9th warmest of the 12 months.
Expect about 9.8 mm of rain on roughly 2 days, which makes August a very dry month (the 3rd driest of the 12 months). Daylight, from sunrise to sunset, lasts about 11 h 12 min on an average August day.
The nearest other city in this atlas is Alberton (11 km away). In August its highs average 20.7°C, 1.3°C warmer than Johannesburg, with 9.8 mm of rain.
Among the 95 cities listed in South Africa, Johannesburg ranks 82nd of 95 for the warmest August highs and joint 27th of 95 for the driest August (rainfall, lowest first). The mean August high of those 95 cities is 21.0°C; Johannesburg is 1.6°C cooler than that mean.
From August to September, average highs rise by 4.0°C to 23.4°C, and monthly rainfall rises from 9.8 mm to 22 mm.
The annual picture
August in context
Monthly rainfall
Average total · mmAverages from hourly ERA5 reanalysis data. Actual weather varies from year to year. How these numbers are calculated
Every month, side by side
Johannesburg climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 24.3°C14.1°C | 14.1°C | 132 | 16.4 | 13.614 h |
| February | 24.1°C13.9°C | 13.9°C | 111 | 14.1 | 13.013 h |
| March | 22.8°C12.3°C | 12.3°C | 89 | 12.7 | 12.312 h |
| April | 20.4°C9.3°C | 9.3°C | 45 | 7.3 | 11.511 h |
| May | 18.4°C5.7°C | 5.7°C | 17 | 2.9 | 10.911 h |
| June | 16.1°C2.9°C | 2.9°C | 7.8 | 1.3 | 10.511 h |
| July | 16.3°C2.2°C | 2.2°C | 3.0 | 0.8 | 10.711 h |
| August, selected | 19.4°C4.9°C | 4.9°C | 9.8 | 2.0 | 11.211 h |
| September | 23.4°C8.5°C | 8.5°C | 22 | 3.7 | 11.912 h |
| October | 24.4°C10.9°C | 10.9°C | 75 | 10.7 | 12.713 h |
| November | 24.1°C12.3°C | 12.3°C | 100 | 14.0 | 13.413 h |
| December | 24.3°C13.7°C | 13.7°C | 138 | 18.0 | 13.714 h |
Rainfall is the average of the 30 separate monthly totals. A rain day is a local calendar day with at least 1 mm of precipitation. Daylight is the calculated sunrise-to-sunset length, not measured sunshine.
Compare places
August in nearby cities
- Alberton in AugustSouth Africa · 11 kmHigh 20.7°C · Low 5.7°C · 9.8 mm rain
- Germiston in AugustSouth Africa · 12 kmHigh 20.5°C · Low 5.6°C · 10 mm rain
- Randburg in AugustSouth Africa · 13 kmHigh 20.5°C · Low 5.8°C · 7.5 mm rain
- Roodepoort in AugustSouth Africa · 18 kmHigh 19.6°C · Low 4.9°C · 9.7 mm rain
- Tokoza in AugustSouth Africa · 19 kmHigh 20.8°C · Low 5.7°C · 10 mm rain
- Soweto in AugustSouth Africa · 20 kmHigh 20.1°C · Low 5.6°C · 9.7 mm rain
- Midrand in AugustSouth Africa · 26 kmHigh 20.4°C · Low 5.6°C · 7.5 mm rain
- Benoni in AugustSouth Africa · 28 kmHigh 20.4°C · Low 5.5°C · 10 mm rain
Read the numbers correctly
Climate, not a promise.
These patterns help compare months. They cannot tell you the weather on a specific day of your trip.
Sources, method and limitsHow these numbers are made (what the highs, lows and rain days mean, the sources and the model cell used for Johannesburg) is explained once on the Johannesburg year overview and on the Sources, method and limits page.
Alberton lies in the same rainfall cell, so its rainfall figures are identical to these; temperatures differ because they come from smaller 0.1° cells.