Climate averages 1991–2020
Cape Town weather
in September.
A mild, moderately wet month: the 9th warmest and the 8th driest of the year.
Long-term climate patterns, not a forecast for a particular trip.
September is a mild month in Cape Town: daytime highs average 17.9°C and nights cool to about 10.8°C. By daytime temperature it is the 9th warmest of the 12 months.
Expect about 51 mm of rain on roughly 8 days, which makes September a moderately wet month (the 8th driest of the 12 months). Daylight, from sunrise to sunset, lasts about 11 h 51 min on an average September day.
The nearest other city in this atlas is Atlantis (40 km away). In September its highs average 17.9°C, about as warm as Cape Town, with 36 mm of rain.
Among the 95 cities listed in South Africa, Cape Town ranks joint 94th of 95 for the warmest September highs and 82nd of 95 for the driest September (rainfall, lowest first). The mean September high of those 95 cities is 24.3°C; Cape Town is 6.4°C cooler than that mean.
From September to October, average highs rise by 2.5°C to 20.4°C, and monthly rainfall falls from 51 mm to 33 mm.
The annual picture
September 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
Cape Town climate table
| Month | Average highHigh / low | Average low | Rainfall mm/month | Rain days ≥1 mm/day | Daylight hours/dayDaylight h/day |
|---|---|---|---|---|---|
| January | 25.6°C17.5°C | 17.5°C | 15 | 2.8 | 14.114 h |
| February | 25.9°C17.7°C | 17.7°C | 14 | 3.0 | 13.313 h |
| March | 24.6°C16.5°C | 16.5°C | 16 | 3.3 | 12.312 h |
| April | 22.0°C14.2°C | 14.2°C | 43 | 5.2 | 11.311 h |
| May | 19.3°C12.1°C | 12.1°C | 67 | 8.4 | 10.410 h |
| June | 16.9°C10.0°C | 10.0°C | 108 | 11.1 | 9.910 h |
| July | 16.4°C9.3°C | 9.3°C | 98 | 9.9 | 10.110 h |
| August | 16.5°C9.5°C | 9.5°C | 87 | 10.3 | 10.911 h |
| September, selected | 17.9°C10.8°C | 10.8°C | 51 | 8.2 | 11.912 h |
| October | 20.4°C12.8°C | 12.8°C | 33 | 5.8 | 12.913 h |
| November | 22.1°C14.4°C | 14.4°C | 30 | 5.1 | 13.914 h |
| December | 24.3°C16.4°C | 16.4°C | 17 | 3.6 | 14.414 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
September in nearby cities
- Atlantis in SeptemberSouth Africa · 40 kmHigh 17.9°C · Low 9.0°C · 36 mm rain
- Somerset West in SeptemberSouth Africa · 41 kmHigh 19.0°C · Low 11.4°C · 68 mm rain
- Stellenbosch in SeptemberSouth Africa · 41 kmHigh 19.0°C · Low 9.4°C · 68 mm rain
- Paarl in SeptemberSouth Africa · 55 kmHigh 19.9°C · Low 9.1°C · 77 mm rain
- Worcester, South Africa in SeptemberSouth Africa · 100 kmHigh 19.9°C · Low 9.8°C · 35 mm rain
- Mossel Bay in SeptemberSouth Africa · 344 kmHigh 19.3°C · Low 11.2°C · 33 mm rain
- Oudtshoorn in SeptemberSouth Africa · 351 kmHigh 22.2°C · Low 8.3°C · 27 mm rain
- George in SeptemberSouth Africa · 373 kmHigh 18.1°C · Low 10.3°C · 44 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 Cape Town) is explained once on the Cape Town year overview and on the Sources, method and limits page.