West Island weather in September

In September, West Island sees average daytime highs of 26°C and overnight lows near 25°C, with 58 mm of rain across 8.7 wet days and about 11.9 hours of daylight. It is the 12th-warmest and 11th-wettest month of the year here.

Day-to-day highs hold fairly steady near 26°C through the month. The sky is clear or mostly clear about 32% of the time in September, and the air most often feels muggy.

Daylight stretches from about 11 h 48 min at the start of September to 12 h 06 min by month's end. Set against the rest of the year, September is West Island's 3rd-clearest and 3rd-windiest month. For the whole year in context, see West Island's year-round climate.

Daytime high: 26°; 12th warmest
Overnight low: 25°; 1st coldest
Rainfall: 58 mm; 8.7 wet days
Daylight: 11 h 54 min; 5:59 AM – 5:55 PM
Cloud cover: 56%; 3rd clearest
Wind: 31 km/h; 3rd windiest
Solar energy: 5.89 kWh/m²
Travel score: 6.9; out of 10

← August West Island 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 26°C through the month.

A typical September day in West Island reaches about 26°C in the afternoon and slips back to 25°C overnight — a 1°C spread between the day's warmth and the night's chill. On most days the high lands between 25°C and 27°C. Set against its neighbours, September runs on par with August and on par with 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)	26	26	26	26	26	26	26	26	26	26	26	26	26	26	26	26	26	26	26	26	26	26	26	26	26	26	26	26	26	26
Avg low (°C)	25	25	25	25	25	25	25	25	25	25	25	25	25	25	25	25	25	25	25	25	25	25	25	25	25	25	25	25	25	25

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

West Island weather by month

How September compares with the rest of the year at a glance. September is the 12th-warmest and 11th-wettest month here — the current month is highlighted below.

Month	High / Low (°C)	Rainfall (mm)	Wet days	Daylight (hours)	Travel score
Jan	27° / 26°	114	13.3	12.6	6.0
Feb	27° / 26°	177	15.6	12.4	5.4
Mar	28° / 26°	201	20.6	12.1	4.9
Apr	28° / 26°	196	20.2	11.7	4.9
May	27° / 26°	132	18.7	11.4	5.3
Jun	27° / 26°	133	17.3	11.3	5.4
Jul	26° / 25°	120	17.6	11.4	5.6
Aug	26° / 25°	62	14.1	11.6	6.2
Sep	26° / 25°	58	8.7	11.9	6.9
Oct	26° / 25°	48	7	12.3	7.2
Nov	26° / 25°	94	8.2	12.6	6.9
Dec	27° / 26°	112	10.5	12.7	6.5

Cloud cover in September

ClearMostly clearPartly cloudyMostly cloudyOvercast

The sky is clear or mostly clear about 32% of the time in September.

Beyond those clear spells, partly cloudy skies cover about 26% of September, with mostly cloudy or overcast conditions the remaining 42%.

	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 (%)	60	60	59	59	59	58	58	57	57	57	56	56	56	57	57	57	57	58	58	57	57	58	58	58	58	58	58	58	58	59
Cloudier (%)	40	40	41	41	41	42	42	43	43	43	44	44	44	43	43	43	43	42	42	43	43	42	42	42	42	42	42	42	42	41

	Clearer (%)	Cloudier (%)
1	60	40
2	60	40
3	59	41
4	59	41
5	59	41
6	58	42
7	58	42
8	57	43
9	57	43
10	57	43
11	56	44
12	56	44
13	56	44
14	57	43
15	57	43
16	57	43
17	57	43
18	58	42
19	58	42
20	57	43
21	57	43
22	58	42
23	58	42
24	58	42
25	58	42
26	58	42
27	58	42
28	58	42
29	58	42
30	59	41

Chance of precipitation in September

Any precipitation

West Island gets around 58 mm of rain over 8.7 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 36% on the wettest days. The odds ease toward the end of the month.

	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 (%)	36	36	36	35	35	34	34	33	32	31	31	30	29	29	28	28	27	27	26	26	26	26	25	25	25	25	25	24	24	24

	Rain chance (%)
1	36
2	36
3	36
4	35
5	35
6	34
7	34
8	33
9	32
10	31
11	31
12	30
13	29
14	29
15	28
16	28
17	27
18	27
19	26
20	26
21	26
22	26
23	25
24	25
25	25
26	25
27	25
28	24
29	24
30	24

Humidity in September

DryComfortableHumidMuggyOppressiveMiserable

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

By dew point, September lands in the muggy band about 52% of days. Sticky, muggy-or-worse air turns up on roughly 97% of them.

	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
Humid (%)	3	3	3	3	3	3	3	3	3	2	2	2	2	2	2	2	2	2	3	3	3	3	3	4	4	4	4	4	4	4
Muggy (%)	47	47	48	48	48	48	48	48	49	49	50	51	51	52	53	53	54	54	54	55	55	56	56	55	55	55	54	54	54	52
Oppressive (%)	48	49	49	49	49	49	49	49	49	48	48	47	47	46	45	45	44	44	43	42	42	41	41	41	41	41	42	42	42	43
Miserable (%)	1	1	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

	Humid (%)	Muggy (%)	Oppressive (%)	Miserable (%)
1	3	47	48	1
2	3	47	49	1
3	3	48	49	0
4	3	48	49	0
5	3	48	49	0
6	3	48	49	0
7	3	48	49	0
8	3	48	49	0
9	3	49	49	0
10	2	49	48	0
11	2	50	48	0
12	2	51	47	0
13	2	51	47	0
14	2	52	46	0
15	2	53	45	0
16	2	53	45	0
17	2	54	44	0
18	2	54	44	0
19	3	54	43	0
20	3	55	42	0
21	3	55	42	0
22	3	56	41	0
23	3	56	41	0
24	4	55	41	0
25	4	55	41	0
26	4	55	41	0
27	4	54	42	0
28	4	54	42	0
29	4	54	42	0
30	4	52	43	1

Wind in September

Winds average 31 km/h in September.

Across September, daily wind ranges from about 31 km/h on the calmest days to 31 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)	31	31	31	31	31	31	31	31	31	31	31	31	31	31	31	31	31	31	31	31	31	31	31	31	31	31	31	31	31	31
Feels	windy	windy	windy	windy	windy	windy	windy	windy	windy	windy	windy	windy	windy	windy	windy	windy	windy	windy	windy	windy	windy	windy	windy	windy	windy	windy	windy	windy	windy	windy

	Wind speed (km/h)	Feels
1	31	windy
2	31	windy
3	31	windy
4	31	windy
5	31	windy
6	31	windy
7	31	windy
8	31	windy
9	31	windy
10	31	windy
11	31	windy
12	31	windy
13	31	windy
14	31	windy
15	31	windy
16	31	windy
17	31	windy
18	31	windy
19	31	windy
20	31	windy
21	31	windy
22	31	windy
23	31	windy
24	31	windy
25	31	windy
26	31	windy
27	31	windy
28	31	windy
29	31	windy
30	31	windy

Sunrise & sunset in September

DaylightNight

Daylight runs from about 11 h 48 min at the start of September to 12 h 06 min by month's end. The lit band spans sunrise to sunset each day.

Days grow by about 18 minutes over September. Sunrise moves from 6:10 AM to 5:49 AM, and sunset from 5:55 PM to 5:55 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)	11.8	11.8	11.8	11.8	11.8	11.8	11.8	11.8	11.9	11.9	11.9	11.9	11.9	11.9	11.9	11.9	11.9	12.0	12.0	12.0	12.0	12.0	12.0	12.0	12.0	12.0	12.1	12.1	12.1	12.1
Sunrise (AM)	6:10	6:09	6:08	6:08	6:07	6:06	6:05	6:05	6:04	6:03	6:03	6:02	6:01	6:00	6:00	5:59	5:58	5:58	5:57	5:56	5:55	5:55	5:54	5:53	5:53	5:52	5:51	5:51	5:50	5:49
Sunset (PM)	5:55	5:55	5:55	5:55	5:55	5:55	5:55	5:55	5:55	5:55	5:55	5:55	5:55	5:55	5:55	5:55	5:55	5:55	5:55	5:55	5:55	5:55	5:55	5:55	5:55	5:55	5:55	5:55	5:55	5:55

	Daylight (h)	Sunrise (AM)	Sunset (PM)
1	11.8	6:10	5:55
2	11.8	6:09	5:55
3	11.8	6:08	5:55
4	11.8	6:08	5:55
5	11.8	6:07	5:55
6	11.8	6:06	5:55
7	11.8	6:05	5:55
8	11.8	6:05	5:55
9	11.9	6:04	5:55
10	11.9	6:03	5:55
11	11.9	6:03	5:55
12	11.9	6:02	5:55
13	11.9	6:01	5:55
14	11.9	6:00	5:55
15	11.9	6:00	5:55
16	11.9	5:59	5:55
17	11.9	5:58	5:55
18	12.0	5:58	5:55
19	12.0	5:57	5:55
20	12.0	5:56	5:55
21	12.0	5:55	5:55
22	12.0	5:55	5:55
23	12.0	5:54	5:55
24	12.0	5:53	5:55
25	12.0	5:53	5:55
26	12.0	5:52	5:55
27	12.1	5:51	5:55
28	12.1	5:51	5:55
29	12.1	5:50	5:55
30	12.1	5:49	5:55

Solar energy in September

Daily solar energy (kWh/m²)

Average shortwave solar energy reaching the ground each day in September, about 5.89 kWh/m².

For context, solar energy here swings from a low near 4.25 kWh/m² to a high of 6.46 kWh/m² in January across the year — September's 5.89 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)	5.5	5.6	5.6	5.6	5.6	5.6	5.7	5.7	5.7	5.7	5.8	5.8	5.8	5.8	5.9	5.9	5.9	6.0	6.0	6.0	6.0	6.1	6.1	6.1	6.1	6.2	6.2	6.2	6.2	6.2
Level	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Bright	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense	Intense

	Solar energy (kWh/m²)	Level
1	5.5	Bright
2	5.6	Bright
3	5.6	Bright
4	5.6	Bright
5	5.6	Bright
6	5.6	Bright
7	5.7	Bright
8	5.7	Bright
9	5.7	Bright
10	5.7	Bright
11	5.8	Bright
12	5.8	Bright
13	5.8	Bright
14	5.8	Bright
15	5.9	Bright
16	5.9	Bright
17	5.9	Bright
18	6.0	Bright
19	6.0	Bright
20	6.0	Intense
21	6.0	Intense
22	6.1	Intense
23	6.1	Intense
24	6.1	Intense
25	6.1	Intense
26	6.2	Intense
27	6.2	Intense
28	6.2	Intense
29	6.2	Intense
30	6.2	Intense

Planning a trip in September

Is September a good time to visit West Island?

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

6.9

Sightseeing

2nd-best month of the year

6.5

Beach & pool

3rd-best month of the year

September is a reasonable time to visit West Island for sightseeing. The water and warmth also suit a beach or pool day.

What to pack for West Island in September

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

In September, West Island sees daytime highs around 26°C and nights near 25°C. Pack a windbreaker. Worth having: light clothes, rain gear and sun protection. About 9 days see rain.

a windbreakerlight clothesrain gearsun protection

Sea temperature near West Island in September

The nearest coast averages about 27°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 March at about 29°C and coldest in September near 27°C.

The water stays above 20°C all year — warm enough for a swim any month.

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Sea temperature (°C)	28	28	29	29	28	28	27	27	27	27	27	27
Comfort	Tropical	Tropical	Tropical	Tropical	Tropical	Warm	Warm	Warm	Warm	Warm	Warm	Warm

	Sea temperature (°C)	Comfort
Jan	28	Tropical
Feb	28	Tropical
Mar	29	Tropical
Apr	29	Tropical
May	28	Tropical
Jun	28	Warm
Jul	27	Warm
Aug	27	Warm
Sep	27	Warm
Oct	27	Warm
Nov	27	Warm
Dec	27	Warm

UV index in West Island in September

LowModerateHighVery highExtreme

Clear-sky midday UV in September peaks around 13 (very high — sun protection essential). The full-year curve, shaded by WHO exposure level, is below.

Under clear skies, the midday UV index in West Island peaks around January 24 at about 15 (extreme) — sunscreen, a hat and midday shade are essential. It bottoms out near June 19 at about 9 (very high).

The index reaches 3 or more — the level where the WHO recommends sun protection — every month of the year.

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
UV index (midday)	15	15	15	12	10	9	10	11	13	14	12	13
Level	Extreme	Extreme	Extreme	Extreme	Extreme	Very high	Very high	Extreme	Extreme	Extreme	Extreme	Extreme

	UV index (midday)	Level
Jan	15	Extreme
Feb	15	Extreme
Mar	15	Extreme
Apr	12	Extreme
May	10	Extreme
Jun	9	Very high
Jul	10	Very high
Aug	11	Extreme
Sep	13	Extreme
Oct	14	Extreme
Nov	12	Extreme
Dec	13	Extreme

Location & terrain

Where is West Island?

West Island sits at 12.2°S, 96.8°E, 12 m above sea level, in Cocos Islands. The nearest listed city is Flying Fish Cove, 985 km away.

Topography around West Island

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

Within 3 km, the terrain around West Island has only modest variations in elevation — a maximum elevation change of 18 m around an average of 1 m above sea level; within 16 km, only modest variations in elevation — a maximum elevation change of 18 m; within 80 km, only modest variations in elevation — a maximum elevation change of 15 m.

3 km

18 m

16 km

18 m

80 km

15 m

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

September weather nearby: Flying Fish Cove 985 km · Bengkulu 1,105 km · Pagar Alam 1,148 km · Curup 1,152 km · Labuan 1,179 km · Lubuklinggau 1,189 km · Lahat 1,189 km · Bandar Lampung 1,191 km

Data sources

Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for West Island (-12.1568°, 96.8225°, elevation 12 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	26	25
2	26	25
3	26	25
4	26	25
5	26	25
6	26	25
7	26	25
8	26	25
9	26	25
10	26	25
11	26	25
12	26	25
13	26	25
14	26	25
15	26	25
16	26	25
17	26	25
18	26	25
19	26	25
20	26	25
21	26	25
22	26	25
23	26	25
24	26	25
25	26	25
26	26	25
27	26	25
28	26	25
29	26	25
30	26	25

	Clearer (%)	Cloudier (%)
1	60	40
2	60	40
3	59	41
4	59	41
5	59	41
6	58	42
7	58	42
8	57	43
9	57	43
10	57	43
11	56	44
12	56	44
13	56	44
14	57	43
15	57	43
16	57	43
17	57	43
18	58	42
19	58	42
20	57	43
21	57	43
22	58	42
23	58	42
24	58	42
25	58	42
26	58	42
27	58	42
28	58	42
29	58	42
30	59	41

	Rain chance (%)
1	36
2	36
3	36
4	35
5	35
6	34
7	34
8	33
9	32
10	31
11	31
12	30
13	29
14	29
15	28
16	28
17	27
18	27
19	26
20	26
21	26
22	26
23	25
24	25
25	25
26	25
27	25
28	24
29	24
30	24

	Humid (%)	Muggy (%)	Oppressive (%)	Miserable (%)
1	3	47	48	1
2	3	47	49	1
3	3	48	49	0
4	3	48	49	0
5	3	48	49	0
6	3	48	49	0
7	3	48	49	0
8	3	48	49	0
9	3	49	49	0
10	2	49	48	0
11	2	50	48	0
12	2	51	47	0
13	2	51	47	0
14	2	52	46	0
15	2	53	45	0
16	2	53	45	0
17	2	54	44	0
18	2	54	44	0
19	3	54	43	0
20	3	55	42	0
21	3	55	42	0
22	3	56	41	0
23	3	56	41	0
24	4	55	41	0
25	4	55	41	0
26	4	55	41	0
27	4	54	42	0
28	4	54	42	0
29	4	54	42	0
30	4	52	43	1

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

	Clearer (%)	Cloudier (%)
1	60	40
2	60	40
3	59	41
4	59	41
5	59	41
6	58	42
7	58	42
8	57	43
9	57	43
10	57	43
11	56	44
12	56	44
13	56	44
14	57	43
15	57	43
16	57	43
17	57	43
18	58	42
19	58	42
20	57	43
21	57	43
22	58	42
23	58	42
24	58	42
25	58	42
26	58	42
27	58	42
28	58	42
29	58	42
30	59	41

	Rain chance (%)
1	36
2	36
3	36
4	35
5	35
6	34
7	34
8	33
9	32
10	31
11	31
12	30
13	29
14	29
15	28
16	28
17	27
18	27
19	26
20	26
21	26
22	26
23	25
24	25
25	25
26	25
27	25
28	24
29	24
30	24

	Humid (%)	Muggy (%)	Oppressive (%)	Miserable (%)
1	3	47	48	1
2	3	47	49	1
3	3	48	49	0
4	3	48	49	0
5	3	48	49	0
6	3	48	49	0
7	3	48	49	0
8	3	48	49	0
9	3	49	49	0
10	2	49	48	0
11	2	50	48	0
12	2	51	47	0
13	2	51	47	0
14	2	52	46	0
15	2	53	45	0
16	2	53	45	0
17	2	54	44	0
18	2	54	44	0
19	3	54	43	0
20	3	55	42	0
21	3	55	42	0
22	3	56	41	0
23	3	56	41	0
24	4	55	41	0
25	4	55	41	0
26	4	55	41	0
27	4	54	42	0
28	4	54	42	0
29	4	54	42	0
30	4	52	43	1

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

	Clearer (%)	Cloudier (%)
1	60	40
2	60	40
3	59	41
4	59	41
5	59	41
6	58	42
7	58	42
8	57	43
9	57	43
10	57	43
11	56	44
12	56	44
13	56	44
14	57	43
15	57	43
16	57	43
17	57	43
18	58	42
19	58	42
20	57	43
21	57	43
22	58	42
23	58	42
24	58	42
25	58	42
26	58	42
27	58	42
28	58	42
29	58	42
30	59	41

	Rain chance (%)
1	36
2	36
3	36
4	35
5	35
6	34
7	34
8	33
9	32
10	31
11	31
12	30
13	29
14	29
15	28
16	28
17	27
18	27
19	26
20	26
21	26
22	26
23	25
24	25
25	25
26	25
27	25
28	24
29	24
30	24

	Humid (%)	Muggy (%)	Oppressive (%)	Miserable (%)
1	3	47	48	1
2	3	47	49	1
3	3	48	49	0
4	3	48	49	0
5	3	48	49	0
6	3	48	49	0
7	3	48	49	0
8	3	48	49	0
9	3	49	49	0
10	2	49	48	0
11	2	50	48	0
12	2	51	47	0
13	2	51	47	0
14	2	52	46	0
15	2	53	45	0
16	2	53	45	0
17	2	54	44	0
18	2	54	44	0
19	3	54	43	0
20	3	55	42	0
21	3	55	42	0
22	3	56	41	0
23	3	56	41	0
24	4	55	41	0
25	4	55	41	0
26	4	55	41	0
27	4	54	42	0
28	4	54	42	0
29	4	54	42	0
30	4	52	43	1