Robertson weather in September

In September, Robertson sees average daytime highs of 20°C and overnight lows near 8°C, with 23 mm of rain across 5.6 wet days and about 11.8 hours of daylight. It is the 9th-warmest and 12th-wettest month of the year here.

Highs climb over the month, from about 19°C in the first days to 21°C by the end. The sky is clear or mostly clear about 46% 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 Robertson's 11th-clearest and 6th-windiest month. For the whole year in context, see Robertson's year-round climate.

Daytime high
20°
9th warmest
Overnight low
4th coldest
Rainfall
23 mm
5.6 wet days
Daylight
11 h 48 min
6:41 AM – 6:29 PM
Cloud cover
44%
11th clearest
Wind
9 km/h
6th windiest
Solar energy
5 kWh/m²
Travel score
7.2
out of 10

Robertson is town in the Western Cape, South Africa.

Density
1,461/km²
people per km²
Founded
1853

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

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Highs climb over the month, from about 19°C in the first days to 21°C by the end.

A typical September day in Robertson reaches about 20°C in the afternoon and slips back to 8°C overnight — a 12°C spread between the day's warmth and the night's chill. On most days the high lands between 14°C and 27°C. Set against its neighbours, September runs about 3°C warmer than August and about 3°C cooler than October.

10°20°30°151015202530
Avg high (°C)Avg low (°C)
1197
2197
3197
4197
5197
6197
7197
8198
9208
10208
11208
12208
13208
14208
15208
16208
17208
18208
19208
20208
21218
22218
23218
24218
25218
26219
27219
28219
29219
30219

Robertson weather by month

How September compares with the rest of the year at a glance. September is the 9th-warmest and 12th-wettest month here — the current month is highlighted below.

MonthHigh / Low (°C)Rainfall (mm)Wet daysDaylight (hours)Travel score
Jan29° / 15°265146.8
Feb29° / 16°244.513.36.8
Mar27° / 14°34612.37.5
Apr24° / 11°325.511.27.9
May21° / 28510.37.4
Jun17° / 336.69.86.3
Jul17° / 356106.1
Aug18° / 346.510.76.5
Sep20° / 235.611.87.2
Oct23° / 10°375.612.97.8
Nov25° / 12°385.513.87.9
Dec28° / 14°254.914.27.5

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 46% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 18% of September, with mostly cloudy or overcast conditions the remaining 36%.

0%25%50%75%100%151015202530
Clearer (%)Cloudier (%)
16634
26634
36634
46634
56634
66634
76535
86535
96436
106436
116337
126337
136337
146238
156337
166337
176238
186238
196238
206238
216238
226238
236238
246337
256337
266337
276337
286337
296337
306436

Chance of precipitation in September

Any precipitation

Robertson gets around 23 mm of rain over 5.6 wet days in September, the driest month. The line is the day-by-day chance of measurable precipitation.

Day to day, the chance of measurable rain averages around 19% and peaks near 20% on the wettest days.

0%10%20%30%151015202530
Rain chance (%)
120
220
320
420
520
620
719
819
919
1019
1119
1219
1319
1419
1519
1619
1719
1819
1919
2019
2119
2219
2319
2419
2518
2618
2718
2818
2917
3017

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 99% of days. It rarely turns muggy — the humid and sticky bands barely register.

0%25%50%75%100%151015202530
Dry (%)Comfortable (%)
11000
21000
31000
41000
51000
61000
7991
8991
9991
10991
11991
12991
13991
14991
15991
16991
17991
18991
19991
20991
21991
22991
23991
24991
25991
26991
27991
28991
29991
301000

Wind in September

Winds average 9 km/h in September.

Across September, daily wind ranges from about 8 km/h on the calmest days to 9 km/h at its breeziest. It stays fairly steady from day to day.

051015151015202530
Wind speed (km/h)Feels
18calm
28calm
38calm
48calm
58calm
68calm
78calm
88calm
98calm
108calm
119calm
129calm
139calm
149calm
159calm
169calm
179calm
189calm
199calm
209calm
219calm
229calm
239calm
249calm
259calm
269calm
279calm
289calm
299calm
309calm

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 7:02 AM to 6:21 AM, and sunset from 6:18 PM to 6:39 PM.

12 AM4 AM8 AM12 PM4 PM8 PM12 AM151015202530
Daylight (h)Sunrise (AM)Sunset (PM)
111.37:026:18
211.37:016:19
311.37:006:19
411.46:586:20
511.46:576:21
611.46:556:22
711.56:546:22
811.56:536:23
911.56:516:24
1011.66:506:24
1111.66:486:25
1211.66:476:26
1311.76:456:26
1411.76:446:27
1511.86:426:28
1611.86:416:29
1711.86:406:29
1811.96:386:30
1911.96:376:31
2011.96:356:31
2112.06:346:32
2212.06:326:33
2312.06:316:34
2412.16:296:34
2512.16:286:35
2612.26:276:36
2712.26:256:36
2812.26:246:37
2912.36:226:38
3012.36:216:39

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 5 kWh/m².

For context, solar energy here swings from a low near 2.63 kWh/m² to a high of 7.98 kWh/m² in December across the year — September's 5 kWh/m² falls in the middle.

0246151015202530
Solar energy (kWh/m²)Level
14.3Bright
24.4Bright
34.4Bright
44.5Bright
54.5Bright
64.5Bright
74.6Bright
84.6Bright
94.7Bright
104.7Bright
114.8Bright
124.8Bright
134.9Bright
144.9Bright
155.0Bright
165.0Bright
175.1Bright
185.1Bright
195.2Bright
205.2Bright
215.3Bright
225.3Bright
235.3Bright
245.4Bright
255.5Bright
265.5Bright
275.5Bright
285.6Bright
295.6Bright
305.7Bright
Planning a trip in September

Is September a good time to visit Robertson?

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

7.2
Sightseeing
7th-best month of the year
3.8
Beach & pool
9th-best month of the year

September is one of the better times to visit Robertson for general sightseeing.

What to pack for Robertson in September

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

In September, Robertson sees daytime highs around 20°C and nights near 8°C. Worth packing: a warm layer and sun protection. About 6 days see rain.

a warm layersun protection

UV index in Robertson 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 Robertson 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
Mar10Very high
Apr6High
May4Moderate
Jun3Moderate
Jul3Moderate
Aug4Moderate
Sep6High
Oct10Extreme
Nov12Extreme
Dec12Extreme

Air quality in Robertson 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 Robertson is worst in June — around 17 µg/m³ PM2.5 (moderate), about 2.9× the cleanest month (January, 6 µg/m³).

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

01020JanFebMarAprMayJunJulAugSepOctNovDecGoodModerateGoodJun 2017 µg/m³Jan 166 µg/m³
PM2.5 (µg/m³)Level
Jan6Good
Feb8Good
Mar9Good
Apr10Good
May16Moderate
Jun17Moderate
Jul17Moderate
Aug16Moderate
Sep13Moderate
Oct9Good
Nov7Good
Dec8Good
Location & terrain

Where is Robertson?

Robertson sits at 33.8°S, 19.9°E, 187 m above sea level, in South Africa. The nearest listed city is Ashton, 16 km away.

Topography around Robertson

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

Within 3 km, the terrain around Robertson has significant variations in elevation — a maximum elevation change of 273 m around an average of 209 m above sea level; within 16 km, very significant variations in elevation — a maximum elevation change of 1,558 m; within 80 km, very significant variations in elevation — a maximum elevation change of 2,214 m.

The land around Robertson is covered by shrubs (42%) and cropland (21%) within 3 km, shrubs (54%) and grassland (26%) within 16 km, and grassland (44%), shrubs (30%) and cropland (21%) within 80 km.

3 km
273 m
16 km
1,558 m
80 km
2,214 m
treesshrubsgrasslandcroplandartificial surfacesbare terrainwater
September weather nearby: Ashton 16 km · Montagu 22 km · Worcester 44 km · Swellendam 57 km · Caledon 64 km · Franschhoek 72 km · Ceres 72 km · Le Roux 73 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 Robertson (-33.8034°, 19.8854°, elevation 187 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. 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).