Kralendijk (Bonaire) weather in September

September in Kralendijk: sweltering, a little rain, with clean air — fine if you can take 38°C afternoons.

Updated September 2026 · climate normals from ERA5 reanalysis

Kralendijk Bonaire · Southern Caribbean · Island85
  1. 88Jan
  2. 89Feb
  3. 90Mar
  4. 89Apr
  5. 88May
  6. 86Jun
  7. 86Jul
  8. 86Aug
  9. 85Sep
  10. 82Oct
  11. 80Nov
  12. 86Dec

#10 of 12 months in Kralendijk · #493 of 1413 destinations to visit in September · comfort 85/100 (tier A)

Days
33°C
Nights
28°C
Wet days
9
Sun
10.8 h
Humidity
79%
Daylight
12 h
Kralendijk, Bonaire
Photo: Vince Colson · Pexels

Traveller notes on Kralendijk in September

Forum posters describe September as genuinely the hottest month of the year here, with less wind than usual making the heat feel more intense - the sun feels noticeably stronger on a still, windless day even for experienced divers and snorkelers. Posters are consistent that Bonaire's rainy season more typically runs October through January, so September itself usually sees comparatively little rain, generally in the form of brief, intense showers that don't meaningfully disrupt diving or snorkeling. Posters note the island stays noticeably quieter in September, with fewer tourists and some restaurants closed for a slower stretch, though Bonaire doesn't see the mass seasonal closures some other Caribbean islands in the hurricane belt experience. Posters generally recommend sun protection given how intense the exposure feels without a cooling breeze.
Tripadvisor community · September · 1 month ago · Read more on Tripadvisor ↗

Other months in Kralendijk

Regulars are specific this island stays genuinely windy nearly all the time, locally known as the westerlies, though snorkeling remains nice in spots that get some natural buffer from the breeze. Our row backs that hot, genuinely wet read, 31.7C reading as a scorching 35C, over 27.1C nights feeling 28C, with 45.2mm of rain across 9.8 days and a real 35.8 kph wind. Regulars are consistent this counts as shoulder or off season, weather-wise barely distinguishable from May, one visitor's mid-June two-week stay specifically reporting favorable conditions and noticeably thinner crowds. The sea sits at a bath-warm 28.2C. The record: 11.3 hours of sun, humidity 81 percent and AQI 56.
AlwaysWindyWesterliesShoulderSeason · June · 1 month ago · Read more on Tripadvisor ↗
May sits inside this island's windier stretch, roughly January through August, and our column carries it at a genuinely high 35.6 kph. Regulars explain why that barely troubles most visitors: the trade winds blow steadily from the east, leaving the leeward west side - where nearly all the diving and snorkeling happens - predictably calm, while the exposed south sites like Margate see more surge on a strong-wind day. Air is 31.3C reading as 35C at 81.4 percent humidity, over 27C nights, with 21.5mm of rain across 5.2 days. The sea is 27.4C. One regular names May and early June as their favourite non-winter stretch specifically because of this wind-shadow effect. The record: 11.2 hours of sun and AQI 57.
WindOnOneSideCalmOnTheOther · May · 1 month ago · Read more on Tripadvisor ↗
On Bonaire the rainy season and the high season are the same months, which sounds like a problem and is not. Regulars describe January days in the mid-eighties Fahrenheit and usually sunny, with rain arriving as a hard, short shower - thirty minutes counts as a long one here, and a whole wet day is the exception. Our 10.4 precipitation days spread just 32.3mm between them, three millimetres each, which is that described in figures. The wind runs January to August at 15 to 20 mph, our row's 33.7 kph, and it keeps the insects down while the dive and snorkel sites stay sheltered on the lee shore. Busier now, but only by this island's standards. The record: 29.9C over 24.8C, a 26.9C sea and AQI 48.
ThirtyMinutesIsALongShower · January · 1 month ago · Read more on Tripadvisor ↗
Our row gives Bonaire 33.3 kph in April, among the windiest figures anywhere here, and regulars explain why it barely matters: the wind blows almost constantly - which is what makes this a windsurfing island - but practically every dive and snorkel site sits on the lee shore, so the same wind is offshore there and the water stays flat. December to May is when the trades help settle the sea, so April is inside the good window. A strong easterly does put surge on the southern sites like Margate and Red Beryl, and the calmer entries are then nearer town. Shore diving is the island's draw, with a warning attached: getting in and out over the rock in gear is the hazardous part. The record: 30.9C over 26.2C, 17mm across 3.9 days, a 26.8C sea and AQI 54.
TheWholeIslandIsTheLee · April · 1 month ago · Read more on Tripadvisor ↗

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Kralendijk climate normals — September

Daytime high33°C / 91°F🔥 sweltering
Nighttime low28°C / 82°F
Feels like (high)38°C / 100°F
Sea temperature30°C / 85°F♨️ bath-warm
Rainfall59 mm / 2.3 in🌦 some rain
Rainy days9 days
Humidity79%💦 very humid
Dew point25°C / 76°F
Sunshine10.8 h/day
Daylight12.2 h
Wind30 km/h / 19 mph
Air quality (US AQI)43🍃 good

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

Crowds in Kralendijk 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.

Quiettravelers describe it as quiet, school holidays in 2 of the markets that fill it

Sourced from traveler notes: “…note the island stays noticeably quieter in September, with fewer tourists and some restaurants closed for a slower stretch, though Bo…” — Tripadvisor community

JFMAMJJASOND

Peak crowdsBusyShoulder seasonQuiet

Best months for Kralendijk'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 weatherKralendijk's weather doesn't swing hard through the year — comfort stays fairly steady in every month.

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What's on in Kralendijk in September

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

  • Nature

    Sea turtle nesting

    1 May – 15 Dec · usually

    Hawksbills and loggerheads nest on Klein Bonaire and the windward beaches from May, and the last hatchlings run down the sand around December. Nests are staked and counted rather than fenced off. Source ↗

What's on around the world in September →

Where is Kralendijk?

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Kralendijk in September — FAQ

Is September a good time to visit Kralendijk?
September in Kralendijk: sweltering, a little rain, with clean air — fine if you can take 38°C afternoons. It ranks #10 of 12 months for Kralendijk on SeasonMap's comfort score (85/100).
What is the weather like in Kralendijk in September?
In September, Kralendijk averages a daily high of 32.9°C and a low of 27.5°C, with about 59.1 mm of rain over roughly 9.4 rainy days.
What is the air quality in Kralendijk in September?
Kralendijk has a mean US Air Quality Index of about 43 in September.