Climate averages 1991–2020
Randburg weather
by month.
See how the year changes. October has the highest average daily maximum; July has the lowest average monthly rainfall.
Pleasant-weather months by our simple rule: AprilMayAugustSeptember
Long-term climate patterns, not a forecast for a particular trip.
Across the year Randburg averages a daytime high of 22.7°C and a nighttime low of 10.2°C, with about 634 mm of rain on roughly 92 days. October is the warmest month (average high 25.6°C) and June the coolest (17.2°C). December is the wettest month with 117 mm; July is the driest with 2.5 mm.
Months with pleasant weather by a simple rule (average high between 18°C and 29°C, average low of at least 5°C and at most 8 rain days): April, May, August and September. This looks at temperature and rain only, not humidity, wind, sea temperature or crowds.
The annual picture
A year in Randburg
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
Randburg climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 25.5°C15.2°C | 15.2°C | 108 | 15.0 | 13.614 h |
| February | 25.4°C14.9°C | 14.9°C | 97 | 12.4 | 13.013 h |
| March | 24.1°C13.4°C | 13.4°C | 80 | 11.1 | 12.312 h |
| April | 21.6°C10.3°C | 10.3°C | 37 | 6.4 | 11.511 h |
| May | 19.6°C6.6°C | 6.6°C | 14 | 2.5 | 10.911 h |
| June | 17.2°C3.7°C | 3.7°C | 6.5 | 1.1 | 10.511 h |
| July | 17.4°C3.1°C | 3.1°C | 2.5 | 0.6 | 10.711 h |
| August | 20.5°C5.8°C | 5.8°C | 7.5 | 1.4 | 11.211 h |
| September | 24.6°C9.5°C | 9.5°C | 19 | 2.8 | 11.912 h |
| October | 25.6°C11.9°C | 11.9°C | 61 | 9.3 | 12.713 h |
| November | 25.2°C13.3°C | 13.3°C | 85 | 12.5 | 13.413 h |
| December | 25.4°C14.8°C | 14.8°C | 117 | 16.4 | 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
Nearby cities
- JohannesburgSouth Africa · 13 kmHigh 21.5°C · Low 9.2°C · 749 mm rain a year
- RoodepoortSouth Africa · 15 kmHigh 21.7°C · Low 9.4°C · 758 mm rain a year
- MidrandSouth Africa · 18 kmHigh 22.5°C · Low 10.2°C · 634 mm rain a year
- GermistonSouth Africa · 21 kmHigh 22.5°C · Low 10.1°C · 719 mm rain a year
- KrugersdorpSouth Africa · 23 kmHigh 21.8°C · Low 9.6°C · 682 mm rain a year
- AlbertonSouth Africa · 23 kmHigh 22.7°C · Low 10.2°C · 749 mm rain a year
- SowetoSouth Africa · 24 kmHigh 22.2°C · Low 10.0°C · 758 mm rain a year
- ThembisaSouth Africa · 25 kmHigh 22.8°C · Low 10.6°C · 645 mm rain a year
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 limitsWhat do the high and low temperatures mean?
We average the daily maximum and daily minimum for each calendar month over 1991–2020. They are not record extremes, a forecast range or temperatures at a fixed time of day.
How is a rain day counted?
A local calendar day (standard time, UTC+2, no daylight saving) with at least 1 mm of total precipitation counts as one rain day. We count these for each year and month, then average across 30 years. The average does not predict which days will be wet.
Where do the numbers come from?
ERA5-Land (temperature) and ERA5 (precipitation) reanalysis from the Copernicus Climate Change Service, read from the Open-Meteo open-data archive. Temperature comes from the 0.1° model cell at -26.10°, 28.00° (1 km from the city centre). Rain comes from the 0.25° cell at -26.00°, 28.00°. Midrand lies in the same rainfall cell, so its rainfall figures are identical to these; temperatures differ because they come from smaller 0.1° cells. These are model estimates, not weather-station readings; coast, hills and city streets can differ.
Does this page show sunshine, humidity or sea temperature?
No. The data used here contain air temperature and precipitation only. Daylight hours are calculated from the city's latitude (sunrise to sunset), not measured sunshine.