Stellenbosch weather in September

In September, Stellenbosch sees average daytime highs of 17°C and overnight lows near 11°C, with 68 mm of rain across 8.8 wet days and about 11.8 hours of daylight. It is the 9th-warmest and 5th-wettest month of the year here.

Day-to-day highs hold fairly steady near 17°C through the month. The sky is clear or mostly clear about 39% of the time in September, and the air most often feels dry.

Daylight stretches from about 11 h 18 min at the start of September to 12 h 18 min by month's end. Set against the rest of the year, September is Stellenbosch's 12th-clearest and 7th-windiest month. For the whole year in context, see Stellenbosch's year-round climate.

Daytime high
17°
9th warmest
Overnight low
11°
4th coldest
Rainfall
68 mm
8.8 wet days
Daylight
11 h 48 min
6:45 AM – 6:33 PM
Cloud cover
49%
12th clearest
Wind
14 km/h
7th windiest
Solar energy
4.8 kWh/m²
Travel score
5.8
out of 10

Stellenbosch is town in the Western Cape, South Africa.

Density
11,678/km²
people per km²
Founded
1679

Air quality: WHO Ambient Air Quality Database. Density & description: Wikidata (CC0), GeoNames.

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 17°C through the month.

A typical September day in Stellenbosch reaches about 17°C in the afternoon and slips back to 11°C overnight — a 7°C spread between the day's warmth and the night's chill. On most days the high lands between 14°C and 21°C. Set against its neighbours, September runs about 1°C warmer than August and about 2°C cooler than October.

10°15°20°25°151015202530
Avg high (°C)Avg low (°C)
11610
21610
31610
41710
51710
61710
71710
81710
91710
101710
111710
121710
131711
141711
151711
161711
171711
181711
191711
201711
211711
221711
231711
241811
251811
261811
271811
281811
291811
301811

Stellenbosch weather by month

How September compares with the rest of the year at a glance. September is the 9th-warmest and 5th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan24° / 17°213.4148.8
Feb25° / 17°183.213.38.7
Mar24° / 16°213.512.38.6
Apr21° / 14°565.711.27.4
May19° / 12°90910.36.4
Jun16° / 10°138119.85.1
Jul16° / 12210.3105.1
Aug16° / 10510.910.75.1
Sep17° / 11°688.811.85.8
Oct19° / 12°456.612.96.9
Nov21° / 14°415.813.87.5
Dec23° / 16°244.214.28.4

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 39% of the time in September, the cloudiest month of the year.

Beyond those clear spells, partly cloudy skies cover about 19% of September, with mostly cloudy or overcast conditions the remaining 42%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
15446
25446
35545
45545
55545
65545
75545
85644
95743
105743
115842
125842
135842
145941
155941
165941
176040
186040
196040
205941
216040
226040
236040
246139
256139
266139
276238
286238
296238
306337

Chance of precipitation in September

Any precipitation

Stellenbosch gets around 68 mm of rain over 8.8 wet days in September. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 29% and peaks near 34% on the wettest days. The odds ease toward the end of the month.

0%10%20%30%40%151015202530
Rain chance (%)
134
233
333
432
532
631
731
830
930
1030
1129
1229
1329
1429
1529
1629
1729
1829
1929
2030
2129
2229
2329
2428
2528
2627
2727
2826
2926
3025

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

Most of September feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.

By dew point, September lands in the dry band about 95% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)
1991
2982
3982
4982
5982
6973
7973
8973
9964
10964
11955
12955
13955
14946
15946
16946
17946
18946
19946
20946
21946
22946
23937
24937
25937
26937
27937
28928
29928
30919

Wind in September

Winds average 14 km/h in September.

Across September, daily wind ranges from about 13 km/h on the calmest days to 14 km/h at its breeziest. It stays fairly steady from day to day.

05101520151015202530
Wind speed (km/h)Feels
113light breeze
213light breeze
314light breeze
414light breeze
514light breeze
614light breeze
714light breeze
814light breeze
914light breeze
1014light breeze
1114light breeze
1214light breeze
1314light breeze
1414light breeze
1514light breeze
1614light breeze
1714light breeze
1814light breeze
1914light breeze
2014light breeze
2114light breeze
2214light breeze
2314light breeze
2414light breeze
2514light breeze
2614light breeze
2714light breeze
2814light breeze
2914light breeze
3014light breeze

Sunrise & sunset in September

DaylightNight

Daylight runs from about 11 h 18 min at the start of September to 12 h 18 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 60 minutes over September. Sunrise moves from 7:06 AM to 6:25 AM, and sunset from 6:22 PM to 6:43 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
111.37:066:22
211.37:056:23
311.37:046:23
411.47:026:24
511.47:016:25
611.47:006:26
711.56:586:26
811.56:576:27
911.56:556:28
1011.66:546:28
1111.66:526:29
1211.66:516:30
1311.76:496:30
1411.76:486:31
1511.86:476:32
1611.86:456:33
1711.86:446:33
1811.96:426:34
1911.96:416:35
2011.96:396:35
2112.06:386:36
2212.06:366:37
2312.06:356:38
2412.16:336:38
2512.16:326:39
2612.26:316:40
2712.26:296:41
2812.26:286:41
2912.36:266:42
3012.36:256:43

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.8 kWh/m².

For context, solar energy here swings from a low near 2.47 kWh/m² to a high of 8.15 kWh/m² in December across the year — September's 4.8 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
14.0Bright
24.1Bright
34.2Bright
44.2Bright
54.3Bright
64.3Bright
74.4Bright
84.4Bright
94.5Bright
104.5Bright
114.6Bright
124.6Bright
134.7Bright
144.7Bright
154.8Bright
164.8Bright
174.9Bright
184.9Bright
195.0Bright
205.0Bright
215.1Bright
225.1Bright
235.2Bright
245.2Bright
255.3Bright
265.3Bright
275.4Bright
285.5Bright
295.5Bright
305.6Bright
Planning a trip in September

Hazard calendar for Stellenbosch

In seasonPeak

In September, Stellenbosch sits inside its rainy season season. The full year is below, with each hazard's peak months called out.

Stellenbosch's rainy season runs May–September, when most of the year's rain falls.

Rainy season
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Is September a good time to visit Stellenbosch?

Our two travel scores rate September for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal).

5.8
Sightseeing
9th-best month of the year
1.5
Beach & pool
9th-best month of the year

September is a reasonable time to visit Stellenbosch for sightseeing.

What to pack for Stellenbosch in September

From September's temperature range, rain chance, sun and wind — what's worth putting in the bag.

In September, Stellenbosch sees daytime highs around 17°C and nights near 11°C. Worth packing: rain gear and sun protection. About 9 days see rain.

rain gearsun protection

Sea temperature near Stellenbosch in September

The nearest coast averages about 15°C in September — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea at the nearest coast (about 21 km away) is warmest in January at about 19°C and coldest in July near 15°C.

The water stays below 20°C all year — cool enough that most swimmers want a wetsuit.

14°16°18°20°JanFebMarAprMayJunJulAugSepOctNovDecbracingcool
Sea temperature (°C)Comfort
Jan19Cool
Feb18Cool
Mar17Cool
Apr16Cool
May16Cool
Jun15Cool
Jul15Bracing
Aug15Bracing
Sep15Cool
Oct16Cool
Nov17Cool
Dec18Cool

UV index in Stellenbosch in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 6 — enough to warrant sun protection. The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in Stellenbosch peaks around January 13 at about 13 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near June 20 at about 3 (moderate).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 11 months of the year.

025710JanFebMarAprMayJunJulAugSepOctNovDecExtremeVery highModerateExtremeJan 13UV 13Jun 20UV 3
UV index (midday)Level
Jan13Extreme
Feb10Very high
Mar9Very high
Apr6High
May3Moderate
Jun3Moderate
Jul3Moderate
Aug4Moderate
Sep6High
Oct10Extreme
Nov11Extreme
Dec12Extreme

Air quality in Stellenbosch in September

GoodModeratePoorUnhealthyVery unhealthy

Average fine-particle pollution (PM2.5) through the year — so you can see where September falls, not just the annual average.

Air quality in Stellenbosch is worst in May — around 52 µg/m³ PM2.5 (poor), about 3.4× the cleanest month (December, 15 µg/m³).

Modeled monthly averages (CAMS reanalysis, 2015–2024).

0204060JanFebMarAprMayJunJulAugSepOctNovDecModeratePoorModerateMay 2152 µg/m³Dec 1516 µg/m³
PM2.5 (µg/m³)Level
Jan20Moderate
Feb19Moderate
Mar28Moderate
Apr41Poor
May52Poor
Jun50Poor
Jul47Poor
Aug41Poor
Sep33Moderate
Oct29Moderate
Nov18Moderate
Dec15Moderate
Location & terrain

Where is Stellenbosch?

Stellenbosch sits at 33.9°S, 18.9°E, 122 m above sea level, in South Africa. The nearest listed city is Kuils River, 15 km away.

Topography around Stellenbosch

How much the land rises and falls, and what covers it, within 3, 16 and 80 km of Stellenbosch.

Within 3 km, the terrain around Stellenbosch has large variations in elevation — a maximum elevation change of 605 m around an average of 167 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,612 m; within 80 km, very significant variations in elevation — a maximum elevation change of 2,073 m.

The land around Stellenbosch is covered by artificial surfaces (29%), grassland (28%) and trees (26%) within 3 km, grassland (45%) and trees (22%) within 16 km, and water (34%) and grassland (25%) within 80 km.

3 km
605 m
16 km
1,612 m
80 km
2,073 m
treesshrubsgrasslandcroplandartificial surfaceswater
September weather nearby: Kuils River 15 km · Kraaifontein 17 km · Somerset West 17 km · Le Roux 22 km · Durbanville 23 km · Franschhoek 23 km · Paarl 24 km · Grabouw 28 km

South Africa travel facts

Travel advisory
Level 2
Exercise Increased Caution
Power plugs
Type C / M / N
230 V · 50 Hz
Prices
≈ 41% of US
price level, 2025
GDP per capita
$6,598
2025
Happiness
5.0 / 10
World Happiness, 2025
Safe drinking water
68%
of population, 2024
Homicide rate
43.7
per 100k, 2022
Road deaths
22.2
per 100k/yr, 2019
Income group
Upper middle
World Bank
English
Very high
EF EPI 602
Religion
Christian 86%or other traditional African religions 5%nothing in particular 5%Muslim 2%

Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Stellenbosch (-33.9346°, 18.8668°, elevation 122 m), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google. Sea temperatures are the NOAA OISST v2.1 1991–2020 monthly climatology (public domain), sampled at the nearest ocean point. UV index is derived from CAMS (Copernicus Atmosphere Monitoring Service) clear-sky UV data — contains modified Copernicus Atmosphere Monitoring Service information. Monthly air-quality (PM2.5) seasonality is from the CAMS EAC4 reanalysis (Copernicus Atmosphere Monitoring Service), scaled to the WHO annual mean where available. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).