Labuan Bajo in September: around 30–33°C with high humidity

Labuan Bajo — September guidance for Labuan Bajo points to daytime temperatures around 30–33°C, high humidity close to 70%, and light to moderate monthly rainfall of about 40–90 mm, based on long-term private climate datasets and a BMKG snapshot for 20 September 2026.

The figures combine historical monthly averages with example daily values and should be used as broad planning guides, not as precise forecasts for future years.

On 20 September 2026, BMKG’s local forecast page for Labuan Bajo reported a temperature of 31°C with 72% humidity around midday, under clear conditions and moderate winds from the north. A separate private forecast service described that date as noticeably cooler than recent historical 20 September averages, with temperatures expected to reach around 30–33°C and a moderate chance of light rain.

EaseWeather’s September 2026 page for Labuan Bajo states that the average temperature at the beginning of the month is 33.3°C, easing to about 30°C toward the end of September. Its regional September summary for East Nusa Tenggara lists Labuan Bajo with typical highs near 33°C and lows around 21°C, together with an average wind speed of about 10 km/h.

The service classifies its September outlook as derived from historical climate data rather than a live numerical forecast model, and notes that daily entries are based on past conditions and climatology. Travellers are therefore advised to check an updated local forecast shortly before departure when making operational decisions for boat trips or island excursions.

How climate averages differ from daily forecasts

Long-term guides emphasise that September remains a hot month in Labuan Bajo. EaseWeather describes highs around 33°C and lows near 21°C for September, with a total of 43.1 mm of rainfall over approximately 14 rainy days and average humidity of 72%. Weather2Travel, which uses different climate datasets, reports typical daytime maximum temperatures of 32–33°C in September, night-time temperatures around 19–23°C, and very high heat and humidity.

These numbers are not strictly contradictory. According to the two guides, some values represent long-term monthly averages, while others describe a “usual” maximum or a typical range on individual days. A late-September day showing around 30°C can therefore sit alongside a broader September picture in which 32–33°C is a common daytime maximum.

Humidity is reported separately from air temperature. EaseWeather’s regional tables indicate an average relative humidity of 72% for Labuan Bajo in September, while Weather2Travel characterises the month as having high or very high heat and humidity in its climate descriptions. That combination can make exertion feel more intense than the raw temperature suggests, especially during exposed hikes or long periods on deck.

Rainfall and “rainy days” definitions

The same two services diverge on rainfall. EaseWeather’s September tables for Labuan Bajo and East Nusa Tenggara give a total of about 43 mm of rain spread over roughly 14 rainy days. Weather2Travel’s climate page, built from its own datasets, presents an average September rainfall of 45 mm in one summary and 93 mm in another, along with 8 days with some rain.

These differences are not explained in detail in the public documentation. They may reflect varying thresholds for classifying a “rainy day,” different observation periods or separate climate baselines, but the exact methodology is not fully spelled out on the pages consulted.

Separate Indonesian government research on Manggarai Barat’s rainfall patterns, using the Schmidt–Ferguson classification, describes the regency’s climate as ranging from relatively wet to somewhat dry depending on location, with September monthly rainfall figures in several stations between roughly 64 mm and 150 mm. Those values sit within the broad range suggested by the private services, though they represent regional agroclimatology rather than visitor-oriented guides.

Practical planning for visitors

For travellers, the main practical implication is that September in Labuan Bajo is typically hot, humid and subject to occasional showers, with sea temperatures around 29°C that support diving and snorkelling. The climate tables are useful for setting expectations about heat, sun exposure and the possibility of rain over the month.

However, a monthly rainfall total does not indicate when showers will occur or how long they will last. For decisions about departure times, marine excursions or demanding hikes, visitors should check a current, date-specific local forecast and any available maritime bulletins from BMKG or port authorities shortly before leaving.

Using climate averages for broad planning and pairing them with updated local weather information offers the most robust basis for comfort and safety decisions during September trips to Labuan Bajo.

Sources

• EaseWeather – September 2026 Weather Labuan Bajo
• BMKG – Prakiraan Cuaca Labuan Bajo
• BAPPEDA Kabupaten Manggarai Barat – Hortikultura climate study (PDF)