Cape Town weather in September
Cape Town averages 18°C by day and 11°C at night in September, with the sea at 14°C and 8 days with at least 1 mm of rain. It warms up by about 3°C into October.
Day
18°C
Night
11°C
Sea
14°C
Rainy days
8
Flight from London
12h
What September feels like
September is mild in Cape Town: good for exploring, not reliably beach weather.
The sea is 14°C: cold for swimming, so plan on a heated pool.
Expect some rain: about 8 days with at least 1 mm.
Of the 48 sun destinations we track, Cape Town is the #48 warmest in September.
Want it warmer in September?
These are hotter than Cape Town this month for at most an hour and a half more flying:
Cape Town weather by month
September is highlighted. Compare with August and October, or see the full year in Cape Town.
Cape Town in September: quick answers
Is Cape Town hot in September?
September is mild in Cape Town: good for exploring, not reliably beach weather. Average highs are 18°C and lows 11°C.
Can you swim in Cape Town in September?
The sea is 14°C: cold for swimming, so plan on a heated pool.
Does it rain in Cape Town in September?
Expect some rain: about 8 days with at least 1 mm.
What is the warmest month in Cape Town?
February, at an average high of 26°C. The coolest is July at 17°C.
How long is the flight to Cape Town from the UK?
About 12h direct from London, estimated from the 9,672 km distance. Check your airline for exact times.
Still choosing? See where is hot in September for every destination ranked by temperature, sea and flight time.
How we measured this
Averages of every day in September from 2016 to 2025, from the Open-Meteo historical weather archive (ECMWF ERA5 reanalysis). Sea temperature is the 2023 to 2025 average from the Open-Meteo marine archive. A rainy day has at least 1 mm of rain. Reanalysis describes an area about 25 km across, so sheltered resorts can run a degree or two warmer. Flight time is a distance-based estimate from London Heathrow.
Planning Cape Town in September?
Save the restaurants, beaches and views you find on TikTok and Instagram for Cape Town straight to a map, then let Dream Trip turn them into a day-by-day plan.
