Bandar Seri Begawan weather in September
Temperature, sea and sunshine in September: long-term averages from 30 years of weather data, not a forecast.
Holiday weather in September
Fair
Best time to visit: July, September – March
What is the weather like in Bandar Seri Begawan in September?
In September, Bandar Seri Begawan is hot: daytime highs average 30 °C, and even at night it stays warm at around 25 °C. The sea averages 30.0 °C – almost as warm as a bath. Expect around 5 hours of sunshine a day. It is the rainy season: rain falls on about 23 days, totalling 188 mm. On about 15 days the thermometer climbs to 30 °C or more. The air is often humid and muggy. All in all, September is a so-so month for a holiday in Bandar Seri Begawan.
September compared
How the weather changes from August to October. Tap a month to open it.
| AugustAug | SeptemberSep | OctoberOct | |
|---|---|---|---|
| Score | 39 | 40 | 42 |
| Day | 30° | 30° | 29° |
| Night | 25° | 25° | 24° |
| Sea | 30° | 30° | 30° |
| Sun | 6 h | 5 h | 5 h |
| Rain days | 22 | 23 | 27 |
More details for September
- Daylight
- 12 h 9 min06:11 – 18:20
- UV index
- 14 · extremeclear sky, noon (estimate)All months
- Muggy days
- 30 daysdew point 18 °C or moreAll months
- Wind
- 10 km/haverage daily peakAll months
- Cloud cover
- 86 %on averageAll months
- Hot days
- 15 days30 °C or moreAll months
- Time zone
- UTC+8Asia/Brunei
How the score comes together
- Temperatureweight 50 %64 %
- Sunshineweight 20 %40 %
- Few rainy daysweight 30 %0 %
Each factor is rated from 0 to 100 % and weighted for the travel style “City break”.
What to pack in September
- Swimwear
- Sunscreen
- Sunglasses & sun hat
- Light, breathable clothes
- Water bottle – drink plenty
- Insect repellent
- Rain jacket or umbrella
Bandar Seri Begawan in September: quick answers
Is Bandar Seri Begawan hot in September?
Yes. In September, Bandar Seri Begawan is hot: daytime highs average 30 °C and nights stay around 25 °C. On about 15 days the thermometer climbs to 30 °C or more.
Can you swim in Bandar Seri Begawan in September?
Yes. In September the sea averages 30.0 °C – almost as warm as a bath.
Does it rain much in Bandar Seri Begawan in September?
It rains often – on about 23 days, adding up to 188 mm.
Bandar Seri Begawan month by month
The whole year in Bandar Seri BegawanAll destinations: BruneiWhere to go in SeptemberSea temperature in September
Climate averages 1996–2025, not a forecast. Data: Copernicus ERA5 / ERA5-Land via Open-Meteo.com (CC BY 4.0), NOAA OISST, WMO 1991–2020 (NOAA NCEI), GeoNames (CC BY 4.0). Sources & licences