Warm in Sep
25°C average high
avg high · 18° at night
25°C+ on 6 in 10 days
South Africa
Cape Town weather in September
Is it warm? Not really. September in Cape Town is cool: afternoons average 18°C and nights 11°C. Most days (80%) peak between 15°C and 23°C.
Cool · average high
18°C
25°C or more on about one in ten days; 20°C or more on about two in ten days.
- Average low11°overnight
- Sea14°average, 2023–2025
- Rainy days545 mm in the month
- SkyOften cloudy48% cloud · 31% clear days
How warm it really gets
Every September afternoon from 2011–2025: 450 days. Most (80%) peaked between 15° and 23°.
September, year by year
The average September high in each year. The warmest, 2019, averaged 21°C; the coolest, 2013, 16°C.
Compared with home
Average September highs. Expect rain on about 5 days (45 mm in a typical month).
- Cape Town18°
- London19°
- Manchester17°
- Dublin17°
- Cork17°
- Belfast16°
- Glasgow16°
Warmer in September, not much further
Flying times are estimates from Dublin; Cape Town is about 12h 45m.
Warm in Sep
28°C average high
avg high · 19° at night
25°C+ on 9 in 10 days
Warm in Sep
28°C average high
avg high · 22° at night
25°C+ on 9 in 10 days
Air: ERA5 reanalysis via Open-Meteo, 2011–2025. Sea: Copernicus Marine analysis via Open-Meteo, 2023–2025. Rainy day = 2 mm or more. Clear day = average cloud cover of 30% or less. These are averages of past weather, not a forecast. Methodology