Swimming in Indonesian Borneo (Kalimantan) in september 2025 Sea temperature by city in september
Do you want to go to the beach in Indonesian Borneo (Kalimantan) in september 2025? Is it the right month to go for pleasant temperatures and staying in the water for a long time? The answer is on this page with the sea temperatures in september in Indonesian Borneo (Kalimantan) by city and our opinion on the chances of enjoying pleasant sea conditions.
Sea temperature in Indonesian Borneo (Kalimantan) in september 2025
Here, find the average sea temperature in Indonesian Borneo (Kalimantan) in september in several coastal cities.
West Kalimantan in september
84°F
min: 82°F / max: 86°F
Mempawah
85°F
min: 83°F / max: 87°F
Pemangkat
85°F
min: 83°F / max: 87°F
Batuampar
84°F
min: 83°F / max: 87°F
Singkawang
85°F
min: 83°F / max: 87°F
East Kalimantan in september
83°F
min: 81°F / max: 86°F
Handil
84°F
min: 81°F / max: 86°F
Bontang
84°F
min: 82°F / max: 87°F
North Kalimantan in september
Bunyu
85°F
min: 83°F / max: 88°F
Sebatik
85°F
min: 83°F / max: 87°F
Where should you go swimming in Indonesian Borneo (Kalimantan) in the month of september?
Swimming in Indonesian Borneo (Kalimantan) in september is ideal
In september in Indonesian Borneo (Kalimantan) swimming conditions are generally the same everywhere.
In september in Pontianak (Borneo), Balikpapan, Bunyu, Handil, Mempawah, Pemangkat, Sebatik, Batuampar, Bontang and Singkawang, swimming conditions are perfect! With water reaching a maximum of 86°F and an average of 84°F, going in the water (and staying there!) feels great.
Where to go swimming in Indonesian Borneo (Kalimantan) in september: the map of sea temperatures
ideal swimming 
pleasant swimming 
cool swimming 
cold swimming 
freezing swimmingWater temperature and seasonal norms in september
Pontianak (Borneo)
| September | |||
| Average sea temperature | 84°F | ||
| Minimum sea temperature | 82°F | ||
| Maximum sea temperature | 86°F | ||
| Average outside temperature | 85°F | ||
| Maximum outside temperature | 92°F | ||
| Minimum outside temperature | 79°F | ||
| Precipitation | 8.2in | ||
| Number of days of precipitation | 12 jour(s) (41%) | ||
| Cloud cover | 40% | ||
| Our opinion | ideal swimming |
More information on swimming in Pontianak (Borneo) in september
Balikpapan
| September | |||
| Average sea temperature | 83°F | ||
| Minimum sea temperature | 81°F | ||
| Maximum sea temperature | 86°F | ||
| Average outside temperature | 85°F | ||
| Maximum outside temperature | 86°F | ||
| Minimum outside temperature | 81°F | ||
| Precipitation | 9.1in | ||
| Number of days of precipitation | 13 jour(s) (44%) | ||
| Cloud cover | 36% | ||
| Our opinion | ideal swimming |
More information on swimming in Balikpapan in september
Bunyu
| September | |||
| Average sea temperature | 85°F | ||
| Minimum sea temperature | 83°F | ||
| Maximum sea temperature | 88°F | ||
| Average outside temperature | 85°F | ||
| Maximum outside temperature | 88°F | ||
| Minimum outside temperature | 81°F | ||
| Precipitation | 12.9in | ||
| Number of days of precipitation | 19 jour(s) (63%) | ||
| Cloud cover | 35% | ||
| Our opinion | ideal swimming |
Handil
| September | |||
| Average sea temperature | 84°F | ||
| Minimum sea temperature | 81°F | ||
| Maximum sea temperature | 86°F | ||
| Average outside temperature | 88°F | ||
| Maximum outside temperature | 92°F | ||
| Minimum outside temperature | 83°F | ||
| Precipitation | 6.8in | ||
| Number of days of precipitation | 12 jour(s) (40%) | ||
| Cloud cover | 37% | ||
| Our opinion | ideal swimming |
Mempawah
| September | |||
| Average sea temperature | 85°F | ||
| Minimum sea temperature | 83°F | ||
| Maximum sea temperature | 87°F | ||
| Average outside temperature | 86°F | ||
| Maximum outside temperature | 90°F | ||
| Minimum outside temperature | 81°F | ||
| Precipitation | 5.9in | ||
| Number of days of precipitation | 9 jour(s) (30%) | ||
| Cloud cover | 40% | ||
| Our opinion | ideal swimming |
List of coastal cities in Indonesian Borneo (Kalimantan)
| Pontianak (Borneo) in september | ideal swimming |
| Balikpapan in september | ideal swimming |
| Bunyu in september | ideal swimming |
| Handil in september | ideal swimming |
| Mempawah in september | ideal swimming |
| Pemangkat in september | ideal swimming |
| Sebatik in september | ideal swimming |
| Batuampar in september | ideal swimming |
| Bontang in september | ideal swimming |
| Singkawang in september | ideal swimming |