Johannesburg weather in September
In September, Johannesburg has an average high of 25 °C77 °F and an average low of 7 °C45 °F, with about 16 mm0.6 in of precipitation. It is the 7th warmest month of the year and ranks 8th for precipitation.
How September compares with other months
Compared with August, September is 4.3 °C7.7 °F warmer on average and wetter by 9 mm0.3 in. Compared with October, September is 2.6 °C4.6 °F cooler on average and drier by 41 mm1.6 in. Daylight lasts about 12.0 hours around the middle of the month. Average relative humidity is 39% and the average cloud amount 29%.
Is September a good time to visit Johannesburg?
Yes — September is one of the most comfortable months to visit Johannesburg by our comfort score, which favours average highs of 21–28 °C, lows above 5 °C, little rain and moderate humidity.
What to wear in September
For Johannesburg in September, pack light summer clothes such as T-shirts, shorts or light dresses and an extra layer for the cooler mornings and evenings.
September in nearby places
| Place | High °C°F | Low °C°F | Precip. mmin |
|---|---|---|---|
| Johannesburg | 2577 | 745 | 160.6 |
| Alberton | 2679 | 847 | 140.6 |
| Roodepoort | 2577 | 745 | 160.6 |
| Soweto | 2678 | 846 | 140.6 |
| Thembisa | 2679 | 847 | 160.6 |
| Krugersdorp | 2577 | 745 | 160.6 |
| Etwatwa | 2679 | 846 | 150.6 |
| Nigel | 2679 | 846 | 150.6 |
| Pretoria | 2883 | 1050 | 130.5 |
Nearby places that are more than 1 °C1.8 °F warmer in September: Alberton, Thembisa, Etwatwa and Nigel.
Other months in Johannesburg
- January27 °C80 °F / 14 °C56 °F
- February27 °C80 °F / 13 °C56 °F
- March25 °C77 °F / 12 °C53 °F
- April22 °C72 °F / 8 °C47 °F
- May19 °C67 °F / 4 °C40 °F
- June16 °C61 °F / 1 °C34 °F
- July16 °C62 °F / 0 °C33 °F
- August20 °C68 °F / 3 °C38 °F
- September25 °C77 °F / 7 °C45 °F
- October27 °C80 °F / 10 °C50 °F
- November27 °C80 °F / 12 °C53 °F
- December27 °C80 °F / 13 °C56 °F
Frequently asked questions
How warm is Johannesburg in September?
In September the average high in Johannesburg is 25 °C (77 °F) and the average low is 7 °C (45 °F).
Does it rain a lot in Johannesburg in September?
On average about 16 mm (0.6 in) of precipitation falls in September; it ranks 8th of the 12 months.
Is September the warmest month in Johannesburg?
No. The warmest month in Johannesburg is November, with an average high of 27 °C (80 °F). The coldest month is July, with an average low of 0 °C (33 °F).
How long is the day in Johannesburg in September?
In the middle of September the day in Johannesburg lasts about 12.0 hours from sunrise to sunset. The value is calculated from the position of the city and the sun.
How humid is Johannesburg in September?
The average relative humidity in September is about 39%. This is a long-term average for the whole day.
How cloudy is Johannesburg in September?
On average about 29% of the sky is covered by cloud in September. This is the mean cloud amount from satellite data, not the number of sunny days.
About this data
All figures are 25-year averages (January 2001 – December 2025) from the NASA POWER project. Temperature, humidity, wind and precipitation come from the MERRA-2 reanalysis (precipitation is the bias-corrected MERRA-2 product), cloud and solar values from CERES satellite data. They describe a grid cell of roughly 50–70 km, not a single weather station, so they can differ from airport records — most of all on coasts, in mountains and for rainfall. Average highs and lows are the monthly mean temperature plus/minus half of the average daily temperature range. Counts of rainy days are not part of this dataset.
The grid cell’s average elevation is 1,538 m, while Johannesburg lies at about 1,767 m. Temperatures on this page were therefore adjusted by −1.5 °C2.7 °F using the standard lapse rate of 6.5 °C per 1,000 m.