September weather - Spring 2023 - Cape Town, South Africa

Weather in September
Frequently asked questions
Average temperature in September
Average pressure in September
Average wind speed in September
Average humidity in September
Average rainfall in September
Average rainfall days in September
Average sea temperature in September
Average daylight in September
Average sunshine in September
Average sunshine days in September
Average UV index in September
Average cloud cover in September
Average visibility in September

Cape Town, South Africa, with the surrounding calm clear waters and several mountains

Weather in September

Spring in Cape Town announces its arrival in September with a marked decrease in rainfall. Nearly drying up to 37mm, this period is characterized by blossoming flora and the rejuvenation of all kinds of outdoor activities. The weather progressively warms up throughout the month, making it pleasant for individuals to soak up the sun and enjoy the outdoors. Transitioning into October, Cape Town divulges into fully-fledged spring, bearing a significant rise in temperature.

Temperature

The average high-temperature for September is a still refreshing 18°C, closely aligning with the temperature of the preceding month. September nights in Cape Town cool down to an average low-temperature of 10.9°C.

Humidity

The months with the highest humidity in Cape Town are June, August and September, with an average relative humidity of 74%.

Rainfall

In Cape Town, in September, it is raining for 11.7 days, with typically 37mm of accumulated precipitation. In Cape Town, during the entire year, the rain falls for 111 days and collects up to 435mm of precipitation.

Sea temperature

July through September, with an average sea temperature of 15.3°C, are months with the coldest seawater in Cape Town, South Africa.
Note: Swimming in 15.3°C is not a pleasurable activity for the majority of people. Breathing becomes increasingly challenging as water temperature descends from 21°C to 15°C.

Daylight

The average length of the day in September in Cape Town is 11h and 53min.
On the first day of September in Cape Town, sunrise is at 07:04 and sunset at 18:28. On the last day of the month, sunrise is at 06:24 and sunset at 18:48 SAST.

Sunshine

In September, the average sunshine is 8h.

UV index

May through September, with an average maximum UV index of 4, are months with the lowest UV index in Cape Town. A UV Index value of 3 to 5 symbolizes a medium health hazard from unsafe exposure to UV radiation for ordinary individuals.
Note: In September, the maximum UV index of 4 suggests this advice:
Take necessary precautions - Suggestions to elude sunburn are provided. The intensity of the Sun's UV radiation during midday suggests reducing time spent outdoors. A wide-brimmed hat is a shield, deflecting up to 50% of harmful UV radiation from eyes.

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FAQ

What is the temperature in September in Cape Town?

September temperatures in Cape Town vary between a high-temperature of 18°C and a low-temperature of 10.9°C.

What is the most humid month in Cape Town?

The months with the highest humidity in Cape Town are June, August and September, with an average relative humidity of 74%.

What is the average humidity in September in Cape Town?

In Cape Town, South Africa, the average relative humidity in September is 74%.

How many days does it rain in September in Cape Town?

In Cape Town, South Africa, during September, the rain falls for 11.7 days and regularly aggregates up to 37mm of precipitation.

What are the months with the coldest sea water in Cape Town?

The months with the coldest seawater in Cape Town, South Africa, are July through September, with an average sea temperature of 15.3°C.

What is the sea water temperature in September in Cape Town?

In Cape Town, South Africa, in September, the average water temperature is 15.3°C. For most, swimming in 15.3°C is not an enjoyable activity. Furthermore, controlling your breathing becomes progressively more difficult as the water temperature decreases from 21°C to 15°C.

How many hours of daylight does Cape Town have in September?

In September, the average day length is 11h and 53min.

When is the sunrise / sunset in September in Cape Town?

In September, on the first day of the month, sunrise is at 07:04 and sunset at 18:28. On the last day of the month, in Cape Town, sunrise is at 06:24 and sunset at 18:48 SAST.

How long on average sun shines in September in Cape Town?

In September, the average sunshine duration in Cape Town, South Africa, is 8h.

What is the month with the lowest UV index in Cape Town?

May through September, with an average maximum UV index of 4, are months with the lowest UV index in Cape Town, South Africa.

What is the UV index reading in September in Cape Town?

In September, the average daily maximum UV index in Cape Town is 4. A UV Index of 3 to 5 symbolizes a medium health risk from exposure to Sun's UV rays.

Today

Tomorrow

Long-term

Year J F M A M J J A September O N D

Aug

September

Oct

Average high temperature

16.6°C

18°C

20.7°C

Average low temperature

Average pressure

Average wind speed

Average max. wind speed

15.5km/h

15.6km/h

17.1km/h

Average wind speed gusts

Average humidity

Average rainfall

Average rainfall days

13.7

11.7

9.4

Average sea temperature

Average daylight

Average sunshine

Average sunshine days

15.3

19.7

Average UV index

Average cloud cover

Average visibility

Average temperature in September
Cape Town, South Africa

Average high temperature in September: 18°C

The warmest month (with the highest average high temperature) is February (26.1°C).
The month with the lowest average high temperature is August (16.6°C).

Average low temperature in September: 10.9°C

The month with the highest average low temperature is January (17.7°C).
The coldest months (with the lowest average low temperature) are July and August (10.2°C).

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Average pressure in September
Cape Town, South Africa

Average pressure in September: 1019.6mbar

The month with the highest atmospheric pressure is July (1022mbar).
The month with the lowest atmospheric pressure is February (1013.4mbar).

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Average wind speed in September
Cape Town, South Africa

Average wind speed in September: 15km/h

The windiest month (with the highest average wind speed) is January (17.6km/h).
The calmest month (with the lowest average wind speed) is May (13.4km/h).

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Average humidity in September
Cape Town, South Africa

Average humidity in September: 74%

The months with the highest relative humidity are June, August and September (74%).
The months with the lowest relative humidity are February, April and December (68%).

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Average rainfall in September
Cape Town, South Africa

Average rainfall in September: 37mm

The wettest month (with the highest rainfall) is June (98mm).
The driest month (with the least rainfall) is February (7mm).

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Average rainfall days in September
Cape Town, South Africa

Average rainfall days in September: 11.7 days

The month with the highest number of rainy days is June (13.8 days).
The month with the least rainy days is February (4.9 days).

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Average sea temperature in September
Cape Town, South Africa

Average sea temperature in September: 15.3°C

The best month for swimming (with the highest average sea temperature) is January (18.5°C).
The coldest months (with the lowest average sea temperature) are July, August and September (15.3°C).

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Average daylight in September /
Average sunshine in September
Cape Town, South Africa

Average daylight in September: 11h and 5min

The month with the longest days is December (Average daylight: 14h and 24min).
The month with the shortest days is June (Average daylight: 9h and 54min).

Average sunshine in September: 8h and 0min

The month with the most sunshine is December (Average sunshine: 11h and 6min).
The month with the least sunshine is June (Average sunshine: 6h and 0min).

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Average sunshine days in September
Cape Town, South Africa

Average sunshine days in September: 16 days

The month with the most sunshine days is January (23.1 days).
The month with the least sunshine days is June (14.6 days).

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Average UV index in September
Cape Town, South Africa

Average UV index in September: 4

The months with the highest UV index are January, February and December (UV index 6).
The months with the lowest UV index are May, June, July, August and September (UV index 4).

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Average cloud cover in September
Cape Town, South Africa

Average cloud cover in September: 33

The month with the most cloud cover is June (Cloud cover 34).
The month with the least cloud cover is February (Cloud cover 15).

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Average visibility in September
Cape Town, South Africa

Average visibility in September: 10km

The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (10km).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (10km).

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September weather forecast
Cape Town, South Africa

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