Knysna weather in September

In September, Knysna sees average daytime highs of 18°C and overnight lows near 11°C, with 49 mm of rain across 8.5 wet days and about 11.8 hours of daylight. It is the 9th-warmest and 7th-wettest month of the year here.

Day-to-day highs hold fairly steady near 18°C through the month. The sky is clear or mostly clear about 41% 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 Knysna's 10th-clearest and 5th-windiest month. For the whole year in context, see Knysna's year-round climate.

Daytime high: 18°; 9th warmest
Overnight low: 11°; 4th coldest
Rainfall: 49 mm; 8.5 wet days
Daylight: 11 h 48 min; 6:28 AM – 6:16 PM
Cloud cover: 48%; 10th clearest
Wind: 14 km/h; 5th windiest
Solar energy: 4.85 kWh/m²
Travel score: 6.2; out of 10

Knysna is town in the Western Cape, South Africa.

Density: 631/km²; people per km²
Founded: 1871

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

← August Knysna year-round climate October →Best places to visit in September

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

Temperature in September

Average highAverage lowShaded bands: 10–90% of days

Day-to-day highs hold fairly steady near 18°C through the month.

A typical September day in Knysna reaches about 18°C in the afternoon and slips back to 11°C overnight — a 6°C spread between the day's warmth and the night's chill. On most days the high lands between 14°C and 22°C. Set against its neighbours, September runs about 1°C warmer than August and about 1°C cooler than October.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Avg high (°C)	18	18	18	18	18	18	18	18	18	18	18	18	18	18	18	18	18	18	18	18	18	18	18	18	18	18	18	18	18	18
Avg low (°C)	11	11	11	11	11	11	11	11	11	11	11	11	11	11	11	12	12	12	12	12	12	12	12	12	12	12	12	12	12	12

	Avg high (°C)	Avg low (°C)
1	18	11
2	18	11
3	18	11
4	18	11
5	18	11
6	18	11
7	18	11
8	18	11
9	18	11
10	18	11
11	18	11
12	18	11
13	18	11
14	18	11
15	18	11
16	18	12
17	18	12
18	18	12
19	18	12
20	18	12
21	18	12
22	18	12
23	18	12
24	18	12
25	18	12
26	18	12
27	18	12
28	18	12
29	18	12
30	18	12

Knysna weather by month

How September compares with the rest of the year at a glance. September is the 9th-warmest and 7th-wettest month here — the current month is highlighted below.

Month	High / Low (°C)	Rainfall (mm)	Wet days	Daylight (hours)	Travel score
Jan	23° / 17°	49	9.2	14	7.3
Feb	23° / 18°	42	7.9	13.3	7.4
Mar	22° / 17°	52	8.5	12.3	7.3
Apr	21° / 14°	52	7.8	11.2	7.0
May	19° / 12°	47	6.7	10.3	6.9
Jun	18° / 11°	43	7.2	9.8	6.5
Jul	17° / 10°	46	7.6	10	6.2
Aug	17° / 10°	62	8.8	10.7	6.0
Sep	18° / 11°	49	8.5	11.8	6.2
Oct	19° / 13°	62	8.9	12.9	6.4
Nov	20° / 14°	70	9.3	13.8	6.6
Dec	22° / 16°	47	9.3	14.2	7.0

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 41% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 21% of September, with mostly cloudy or overcast conditions the remaining 38%. Skies tend to cloud over as the month goes on.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Clearer (%)	67	67	66	66	65	65	65	64	64	63	63	63	63	63	63	62	62	62	61	61	61	61	60	60	58	58	58	57	57	57
Cloudier (%)	33	33	34	34	35	35	35	36	36	37	37	37	37	37	37	38	38	38	39	39	39	39	40	40	42	42	42	43	43	43

	Clearer (%)	Cloudier (%)
1	67	33
2	67	33
3	66	34
4	66	34
5	65	35
6	65	35
7	65	35
8	64	36
9	64	36
10	63	37
11	63	37
12	63	37
13	63	37
14	63	37
15	63	37
16	62	38
17	62	38
18	62	38
19	61	39
20	61	39
21	61	39
22	61	39
23	60	40
24	60	40
25	58	42
26	58	42
27	58	42
28	57	43
29	57	43
30	57	43

Chance of precipitation in September

Any precipitation

Knysna gets around 49 mm of rain over 8.5 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 28% and peaks near 30% on the wettest days.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Rain chance (%)	27	27	27	27	27	27	27	27	27	27	27	27	28	28	28	28	29	29	29	29	30	30	30	30	30	30	30	29	29	29

	Rain chance (%)
1	27
2	27
3	27
4	27
5	27
6	27
7	27
8	27
9	27
10	27
11	27
12	27
13	28
14	28
15	28
16	28
17	29
18	29
19	29
20	29
21	30
22	30
23	30
24	30
25	30
26	30
27	30
28	29
29	29
30	29

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 90% of days. It rarely turns muggy — the humid and sticky bands barely register.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Dry (%)	96	96	96	96	96	95	95	94	94	93	92	91	91	90	89	89	88	88	88	87	87	87	87	87	86	86	85	84	83	83
Comfortable (%)	4	4	4	4	4	5	5	6	6	7	8	9	9	10	11	11	12	12	12	13	13	13	13	13	14	14	15	15	16	16
Humid (%)	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	0	1	1	1

	Dry (%)	Comfortable (%)	Humid (%)
1	96	4	0
2	96	4	0
3	96	4	0
4	96	4	0
5	96	4	0
6	95	5	0
7	95	5	0
8	94	6	0
9	94	6	0
10	93	7	0
11	92	8	0
12	91	9	0
13	91	9	0
14	90	10	0
15	89	11	0
16	89	11	0
17	88	12	0
18	88	12	0
19	88	12	0
20	87	13	0
21	87	13	0
22	87	13	0
23	87	13	0
24	87	13	0
25	86	14	0
26	86	14	0
27	85	15	0
28	84	15	1
29	83	16	1
30	83	16	1

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.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Wind speed (km/h)	13	13	13	13	13	13	13	13	13	13	14	14	14	14	14	14	14	14	14	14	14	14	14	14	14	14	14	14	14	14
Feels	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze	light breeze

	Wind speed (km/h)	Feels
1	13	light breeze
2	13	light breeze
3	13	light breeze
4	13	light breeze
5	13	light breeze
6	13	light breeze
7	13	light breeze
8	13	light breeze
9	13	light breeze
10	13	light breeze
11	14	light breeze
12	14	light breeze
13	14	light breeze
14	14	light breeze
15	14	light breeze
16	14	light breeze
17	14	light breeze
18	14	light breeze
19	14	light breeze
20	14	light breeze
21	14	light breeze
22	14	light breeze
23	14	light breeze
24	14	light breeze
25	14	light breeze
26	14	light breeze
27	14	light breeze
28	14	light breeze
29	14	light breeze
30	14	light 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 6:50 AM to 6:08 AM, and sunset from 6:05 PM to 6:26 PM.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Daylight (h)	11.3	11.3	11.3	11.4	11.4	11.4	11.5	11.5	11.5	11.6	11.6	11.6	11.7	11.7	11.8	11.8	11.8	11.9	11.9	11.9	12.0	12.0	12.0	12.1	12.1	12.2	12.2	12.2	12.3	12.3
Sunrise (AM)	6:50	6:48	6:47	6:46	6:44	6:43	6:41	6:40	6:39	6:37	6:36	6:34	6:33	6:31	6:30	6:28	6:27	6:25	6:24	6:23	6:21	6:20	6:18	6:17	6:15	6:14	6:12	6:11	6:10	6:08
Sunset (PM)	6:05	6:06	6:07	6:07	6:08	6:09	6:09	6:10	6:11	6:12	6:12	6:13	6:14	6:14	6:15	6:16	6:17	6:17	6:18	6:19	6:19	6:20	6:21	6:22	6:22	6:23	6:24	6:25	6:25	6:26

	Daylight (h)	Sunrise (AM)	Sunset (PM)
1	11.3	6:50	6:05
2	11.3	6:48	6:06
3	11.3	6:47	6:07
4	11.4	6:46	6:07
5	11.4	6:44	6:08
6	11.4	6:43	6:09
7	11.5	6:41	6:09
8	11.5	6:40	6:10
9	11.5	6:39	6:11
10	11.6	6:37	6:12
11	11.6	6:36	6:12
12	11.6	6:34	6:13
13	11.7	6:33	6:14
14	11.7	6:31	6:14
15	11.8	6:30	6:15
16	11.8	6:28	6:16
17	11.8	6:27	6:17
18	11.9	6:25	6:17
19	11.9	6:24	6:18
20	11.9	6:23	6:19
21	12.0	6:21	6:19
22	12.0	6:20	6:20
23	12.0	6:18	6:21
24	12.1	6:17	6:22
25	12.1	6:15	6:22
26	12.2	6:14	6:23
27	12.2	6:12	6:24
28	12.2	6:11	6:25
29	12.3	6:10	6:25
30	12.3	6:08	6:26

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 4.85 kWh/m².

For context, solar energy here swings from a low near 2.65 kWh/m² to a high of 7.48 kWh/m² in December across the year — September's 4.85 kWh/m² falls in the middle.

	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15	16	17	18	19	20	21	22	23	24	25	26	27	28	29	30
Solar energy (kWh/m²)	4.3	4.3	4.3	4.4	4.4	4.4	4.5	4.5	4.6	4.6	4.7	4.7	4.7	4.8	4.8	4.9	4.9	5.0	5.0	5.0	5.1	5.1	5.1	5.2	5.2	5.2	5.3	5.3	5.3	5.4
Level	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright

	Solar energy (kWh/m²)	Level
1	4.3	Bright
2	4.3	Bright
3	4.3	Bright
4	4.4	Bright
5	4.4	Bright
6	4.4	Bright
7	4.5	Bright
8	4.5	Bright
9	4.6	Bright
10	4.6	Bright
11	4.7	Bright
12	4.7	Bright
13	4.7	Bright
14	4.8	Bright
15	4.8	Bright
16	4.9	Bright
17	4.9	Bright
18	5.0	Bright
19	5.0	Bright
20	5.0	Bright
21	5.1	Bright
22	5.1	Bright
23	5.1	Bright
24	5.2	Bright
25	5.2	Bright
26	5.2	Bright
27	5.3	Bright
28	5.3	Bright
29	5.3	Bright
30	5.4	Bright

Planning a trip in September

Is September a good time to visit Knysna?

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

6.2

Sightseeing

10th-best month of the year

2.0

Beach & pool

9th-best month of the year

September is a reasonable time to visit Knysna for sightseeing.

What to pack for Knysna in September

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

In September, Knysna sees daytime highs around 18°C and nights near 11°C. Worth packing: rain gear and sun protection. About 9 days see rain.

rain gearsun protection

Sea temperature near Knysna in September

The nearest coast averages about 17°C in September — the other half of the beach question. The full-year curve and swim-comfort zones are below.

The sea offshore is warmest in January at about 21°C and coldest in August near 17°C.

It's comfortable for a long swim from Dec 20 to Mar 14 — about 2.8 months when the water holds above 20°C.

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Sea temperature (°C)	21	21	20	18	18	17	17	17	17	17	18	20
Comfort	Refreshing	Refreshing	Refreshing	Cool	Cool	Cool	Cool	Cool	Cool	Cool	Cool	Cool

	Sea temperature (°C)	Comfort
Jan	21	Refreshing
Feb	21	Refreshing
Mar	20	Refreshing
Apr	18	Cool
May	18	Cool
Jun	17	Cool
Jul	17	Cool
Aug	17	Cool
Sep	17	Cool
Oct	17	Cool
Nov	18	Cool
Dec	20	Cool

UV index in Knysna 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 Knysna peaks around January 15 at about 13 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near June 23 at about 3 (moderate).

The index reaches 3 or more — the level where the WHO recommends sun protection — in 10 months of the year.

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
UV index (midday)	13	11	9	6	4	3	3	4	6	10	11	12
Level	Extreme	Extreme	Very high	High	Moderate	Moderate	Moderate	Moderate	High	Extreme	Extreme	Extreme

	UV index (midday)	Level
Jan	13	Extreme
Feb	11	Extreme
Mar	9	Very high
Apr	6	High
May	4	Moderate
Jun	3	Moderate
Jul	3	Moderate
Aug	4	Moderate
Sep	6	High
Oct	10	Extreme
Nov	11	Extreme
Dec	12	Extreme

Location & terrain

Where is Knysna?

Knysna sits at 34.0°S, 23.0°E, 9 m above sea level, in South Africa. The nearest listed city is Plettenberg Bay, 30 km away.

Topography around Knysna

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

Within 3 km, the terrain around Knysna has significant variations in elevation — a maximum elevation change of 288 m around an average of 64 m above sea level; within 16 km, large variations in elevation — a maximum elevation change of 929 m; within 80 km, very significant variations in elevation — a maximum elevation change of 2,052 m.

The land around Knysna is covered by trees (41%) and water (20%) within 3 km, trees (45%) and water (34%) within 16 km, and water (36%) and grassland (31%) within 80 km.

3 km

288 m

trees 41%

16 km

929 m

trees 45%

80 km

2,052 m

water 36%

treesshrubsgrasslandcroplandartificial surfaceswaterwetland

← August Knysna year-round climate October →Best places to visit in September

September weather nearby: Plettenberg Bay 30 km · George 55 km · Groot-Brakrivier 76 km · Dysselsdorp 76 km · Mossel Bay 85 km · Oudtshoorn 92 km · Kruisfontein 155 km · Humansdorp 159 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

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 Knysna (-34.0363°, 23.0471°, elevation 9 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. Topography is sampled from the Copernicus DEM GLO-90 elevation model (© ESA/Airbus) and ESA WorldCover 2021 land cover (CC BY 4.0).

	Avg high (°C)	Avg low (°C)
1	18	11
2	18	11
3	18	11
4	18	11
5	18	11
6	18	11
7	18	11
8	18	11
9	18	11
10	18	11
11	18	11
12	18	11
13	18	11
14	18	11
15	18	11
16	18	12
17	18	12
18	18	12
19	18	12
20	18	12
21	18	12
22	18	12
23	18	12
24	18	12
25	18	12
26	18	12
27	18	12
28	18	12
29	18	12
30	18	12

	Clearer (%)	Cloudier (%)
1	67	33
2	67	33
3	66	34
4	66	34
5	65	35
6	65	35
7	65	35
8	64	36
9	64	36
10	63	37
11	63	37
12	63	37
13	63	37
14	63	37
15	63	37
16	62	38
17	62	38
18	62	38
19	61	39
20	61	39
21	61	39
22	61	39
23	60	40
24	60	40
25	58	42
26	58	42
27	58	42
28	57	43
29	57	43
30	57	43

	Rain chance (%)
1	27
2	27
3	27
4	27
5	27
6	27
7	27
8	27
9	27
10	27
11	27
12	27
13	28
14	28
15	28
16	28
17	29
18	29
19	29
20	29
21	30
22	30
23	30
24	30
25	30
26	30
27	30
28	29
29	29
30	29

	Dry (%)	Comfortable (%)	Humid (%)
1	96	4	0
2	96	4	0
3	96	4	0
4	96	4	0
5	96	4	0
6	95	5	0
7	95	5	0
8	94	6	0
9	94	6	0
10	93	7	0
11	92	8	0
12	91	9	0
13	91	9	0
14	90	10	0
15	89	11	0
16	89	11	0
17	88	12	0
18	88	12	0
19	88	12	0
20	87	13	0
21	87	13	0
22	87	13	0
23	87	13	0
24	87	13	0
25	86	14	0
26	86	14	0
27	85	15	0
28	84	15	1
29	83	16	1
30	83	16	1

	Avg high (°C)	Avg low (°C)
1	18	11
2	18	11
3	18	11
4	18	11
5	18	11
6	18	11
7	18	11
8	18	11
9	18	11
10	18	11
11	18	11
12	18	11
13	18	11
14	18	11
15	18	11
16	18	12
17	18	12
18	18	12
19	18	12
20	18	12
21	18	12
22	18	12
23	18	12
24	18	12
25	18	12
26	18	12
27	18	12
28	18	12
29	18	12
30	18	12

	Clearer (%)	Cloudier (%)
1	67	33
2	67	33
3	66	34
4	66	34
5	65	35
6	65	35
7	65	35
8	64	36
9	64	36
10	63	37
11	63	37
12	63	37
13	63	37
14	63	37
15	63	37
16	62	38
17	62	38
18	62	38
19	61	39
20	61	39
21	61	39
22	61	39
23	60	40
24	60	40
25	58	42
26	58	42
27	58	42
28	57	43
29	57	43
30	57	43

	Rain chance (%)
1	27
2	27
3	27
4	27
5	27
6	27
7	27
8	27
9	27
10	27
11	27
12	27
13	28
14	28
15	28
16	28
17	29
18	29
19	29
20	29
21	30
22	30
23	30
24	30
25	30
26	30
27	30
28	29
29	29
30	29

	Dry (%)	Comfortable (%)	Humid (%)
1	96	4	0
2	96	4	0
3	96	4	0
4	96	4	0
5	96	4	0
6	95	5	0
7	95	5	0
8	94	6	0
9	94	6	0
10	93	7	0
11	92	8	0
12	91	9	0
13	91	9	0
14	90	10	0
15	89	11	0
16	89	11	0
17	88	12	0
18	88	12	0
19	88	12	0
20	87	13	0
21	87	13	0
22	87	13	0
23	87	13	0
24	87	13	0
25	86	14	0
26	86	14	0
27	85	15	0
28	84	15	1
29	83	16	1
30	83	16	1

	Avg high (°C)	Avg low (°C)
1	18	11
2	18	11
3	18	11
4	18	11
5	18	11
6	18	11
7	18	11
8	18	11
9	18	11
10	18	11
11	18	11
12	18	11
13	18	11
14	18	11
15	18	11
16	18	12
17	18	12
18	18	12
19	18	12
20	18	12
21	18	12
22	18	12
23	18	12
24	18	12
25	18	12
26	18	12
27	18	12
28	18	12
29	18	12
30	18	12

	Clearer (%)	Cloudier (%)
1	67	33
2	67	33
3	66	34
4	66	34
5	65	35
6	65	35
7	65	35
8	64	36
9	64	36
10	63	37
11	63	37
12	63	37
13	63	37
14	63	37
15	63	37
16	62	38
17	62	38
18	62	38
19	61	39
20	61	39
21	61	39
22	61	39
23	60	40
24	60	40
25	58	42
26	58	42
27	58	42
28	57	43
29	57	43
30	57	43

	Rain chance (%)
1	27
2	27
3	27
4	27
5	27
6	27
7	27
8	27
9	27
10	27
11	27
12	27
13	28
14	28
15	28
16	28
17	29
18	29
19	29
20	29
21	30
22	30
23	30
24	30
25	30
26	30
27	30
28	29
29	29
30	29

	Dry (%)	Comfortable (%)	Humid (%)
1	96	4	0
2	96	4	0
3	96	4	0
4	96	4	0
5	96	4	0
6	95	5	0
7	95	5	0
8	94	6	0
9	94	6	0
10	93	7	0
11	92	8	0
12	91	9	0
13	91	9	0
14	90	10	0
15	89	11	0
16	89	11	0
17	88	12	0
18	88	12	0
19	88	12	0
20	87	13	0
21	87	13	0
22	87	13	0
23	87	13	0
24	87	13	0
25	86	14	0
26	86	14	0
27	85	15	0
28	84	15	1
29	83	16	1
30	83	16	1