West Island (Keeling Islands) weather in September

September in West Island: hot, a little rain, with muggy air — one of the best months to visit.

Updated September 2026 · climate normals from ERA5 reanalysis

West Island Cocos (Keeling) Islands · Java, Bali & Nusa Tenggara · Island86
  1. 80Jan
  2. 78Feb
  3. 71Mar
  4. 78Apr
  5. 78May
  6. 70Jun
  7. 80Jul
  8. 83Aug
  9. 86Sep
  10. 89Oct
  11. 83Nov
  12. 79Dec

#2 of 12 months in West Island · #471 of 1413 destinations to visit in September · comfort 86/100 (tier A)

Days
29°C
Nights
24°C
Wet days
9
Sun
10.5 h
Humidity
77%
Daylight
12 h
West Island, Cocos (Keeling) Islands
Photo: paullymac · CC BY-SA 2.0

Traveller notes on West Island in September

Other months in West Island

Cocos (Keeling) Islands forum posters describe the climate as close to a permanent 28C, with a near-constant wind except during the 'doldrums' stretch from December into January or February, when the air goes hot and still. Locals specifically steer visitors away from that doldrums window and toward the rest of the year instead, which puts April - well clear of the doldrums but still ahead of the widely recommended July-through-October peak - in solid shape for steady breeze and the island's usual warm, settled conditions.
CocosKeelingRegular · April · 1 month ago · Read more on Tripadvisor ↗
Forum posters describe October in the Cocos (Keeling) Islands as genuinely beautiful, with temperatures holding constant in the 23-31C range, alongside increased humidity but less wind than the windier winter months. Posters describe a clear seasonal pattern here: November through March runs balmy with just slight breezes, July through September brings the strongest winds (prime kite and wind-surfing season), and October sits as the standout transition month with the calmer, most pleasant conditions of the year. Posters generally rate the islands as a year-round paradise regardless of season, but consistently single out October specifically for combining warm, settled weather with a welcome break from the stronger winds of the preceding months.
Tripadvisor community · October · 1 month ago · Read more on Tripadvisor ↗

Add your own note from West Island's card on the map.

West Island climate normals — September

Daytime high29°C / 83°F🥵 hot
Nighttime low24°C / 76°F
Feels like (high)29°C / 84°F
Sea temperature26°C / 79°F😎 warm sea
Rainfall60 mm / 2.4 in🌦 some rain
Rainy days9 days
Humidity77%💦 very humid
Dew point22°C / 71°F
Sunshine10.5 h/day
Daylight12 h
Wind36 km/h / 22 mph
Air quality (US AQI)62🙂 moderate

Monthly averages from ERA5 reanalysis. AQI is the mean US Air Quality Index for the month.

Crowds in West Island in September

How busy the place itself is — school and mass holidays, the months an editor tagged, and how sought-after the weather makes them. Never part of the comfort score.

Busyschool holidays in 3 of the markets that fill it, one of its best months for weather(estimated)

JFMAMJJASOND

Peak crowdsBusyShoulder seasonQuiet

Best months for West Island's weather

Ranked by this destination's own climate comfort score across the year — a different thing from how busy it gets (see Crowds above).

Fair weatherWest Island's weather doesn't swing hard through the year — comfort stays fairly steady in every month.

JFMAMJJASOND

What's on in West Island in September

Recurring seasonal events, natural spectacles, closures and holidays — curated and sourced.

  • Season

    Trade wind season

    1 May – 31 Oct · usually

    Southeast trade winds hold for about nine months of the year, but the steadiest stretch for kitesurfing across the lagoon runs May to October. The rest of the year, the doldrums, brings lighter and far more variable wind. Source ↗

What's on around the world in September →

Where is West Island?

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West Island in September — FAQ

Is September a good time to visit West Island?
September in West Island: hot, a little rain, with muggy air — one of the best months to visit. It ranks #2 of 12 months for West Island on SeasonMap's comfort score (86/100).
What is the weather like in West Island in September?
In September, West Island averages a daily high of 28.5°C and a low of 24.4°C, with about 60.2 mm of rain over roughly 9.4 rainy days.
What is the air quality in West Island in September?
West Island has a mean US Air Quality Index of about 62 in September.