Surabaya 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
Good
Best time to visit: June – September
What is the weather like in Surabaya in September?
In September, Surabaya is hot: daytime highs average 33 °C, and even at night it stays warm at around 25 °C. The sea averages 28.6 °C – lovely and warm for swimming. The sun shines for around 9 hours a day. Rain is rare: about 4 days bring 24 mm in total. On about 29 days the thermometer climbs to 30 °C or more. The air is often humid and muggy. All in all, September is a good month for a holiday in Surabaya.
September compared
How the weather changes from August to October. Tap a month to open it.
| AugustAug | SeptemberSep | OctoberOct | |
|---|---|---|---|
| Score | 70 | 62 | 40 |
| Day | 32° | 33° | 33° |
| Night | 24° | 25° | 25° |
| Sea | 28° | 29° | 29° |
| Sun | 9 h | 9 h | 8 h |
| Rain days | 2 | 4 | 13 |
More details for September
- Daylight
- 12 h 3 min05:23 – 17:26
- UV index
- 13 · extremeclear sky, noon (estimate)All months
- Muggy days
- 29 daysdew point 18 °C or moreAll months
- Wind
- 13 km/haverage daily peakAll months
- Cloud cover
- 49 %on averageAll months
- Hot days
- 29 days30 °C or moreAll months
- Time zone
- UTC+7Asia/Jakarta
How the score comes together
- Temperatureweight 50 %26 %
- Sunshineweight 20 %97 %
- Few rainy daysweight 30 %100 %
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
Surabaya in September: quick answers
Is Surabaya hot in September?
Yes. In September, Surabaya is hot: daytime highs average 33 °C and nights stay around 25 °C. On about 29 days the thermometer climbs to 30 °C or more.
Can you swim in Surabaya in September?
Yes. In September the sea averages 28.6 °C – lovely and warm for swimming.
Does it rain much in Surabaya in September?
Rain is rare: about 4 days bring 24 mm in total.
Surabaya month by month
The whole year in SurabayaAll destinations: IndonesiaWhere 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