Climate averages 1991–2020
Johannesburg weather
in January.
A warm, wet month: the joint 2nd warmest and the 11th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
January is a warm month in Johannesburg: daytime highs average 24.3°C and nights cool to about 14.1°C. By daytime temperature it is the joint 2nd warmest of the 12 months.
Expect about 132 mm of rain on roughly 16 days, which makes January a wet month (the 11th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 13 h 34 min on an average January day.
The nearest other city in this atlas is Alberton (11 km away). In January its highs average 25.4°C, 1.1°C warmer than Johannesburg, with 132 mm of rain.
Among the 95 cities listed in South Africa, Johannesburg ranks 90th of 95 for the warmest January highs and joint 72nd of 95 for the driest January (rainfall, lowest first). The mean January high of those 95 cities is 27.0°C; Johannesburg is 2.7°C cooler than that mean.
From January to February, average highs fall by 0.2°C to 24.1°C, and monthly rainfall falls from 132 mm to 111 mm.
The annual picture
January 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, selected | 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 | 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
January in nearby cities
- Alberton in JanuarySouth Africa · 11 kmHigh 25.4°C · Low 15.2°C · 132 mm rain
- Germiston in JanuarySouth Africa · 12 kmHigh 25.2°C · Low 15.0°C · 127 mm rain
- Randburg in JanuarySouth Africa · 13 kmHigh 25.5°C · Low 15.2°C · 108 mm rain
- Roodepoort in JanuarySouth Africa · 18 kmHigh 24.5°C · Low 14.3°C · 132 mm rain
- Tokoza in JanuarySouth Africa · 19 kmHigh 25.5°C · Low 15.3°C · 127 mm rain
- Soweto in JanuarySouth Africa · 20 kmHigh 25.0°C · Low 14.9°C · 132 mm rain
- Midrand in JanuarySouth Africa · 26 kmHigh 25.4°C · Low 15.1°C · 108 mm rain
- Benoni in JanuarySouth Africa · 28 kmHigh 25.0°C · Low 14.8°C · 127 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.