Water temperature in Otaru in September
Is it warm enough to swim in Otaru in September? Average water temperature in Otaru in September is 21.6°C and therefore suitable for comfortable swimming. The warmest sea in Otaru in September is 26.4°C, and the coldest is 18.2°C. Average high air temperature in Otaru in September is 22°C, and average low temperature is 14°C. To find out the sea temperature today and in the coming days, go to Current sea temperature in Otaru
Changes water temperature in Otaru in September 2025, 2024
To get an accurate forecast for the water temperature in Otaru for any chosen month, compare two years within a 10 year range using the chart below. In addition to the sea water temperature in Otaru, the selected years in the table also show the values of the maximum and minimum temperatures on each of the days of September.
You can choose any other years:
| Day | 2025 | 2024 | Min | Max |
|---|---|---|---|---|
| 1 September | 24.4°C | 23.7°C | 20.1°C | 25.6°C |
| 2 September | 24.4°C | 23.8°C | 20.2°C | 24.8°C |
| 3 September | 24.3°C | 23.7°C | 20.2°C | 25.3°C |
| 4 September | 24.2°C | 23.3°C | 20.3°C | 25.7°C |
| 5 September | 24.9°C | 23.3°C | 20.6°C | 25.3°C |
| 6 September | 24.6°C | 23.6°C | 20.8°C | 24.7°C |
| 7 September | 24.3°C | 23.5°C | 20.6°C | 24.3°C |
| 8 September | 24.1°C | 23.5°C | 20.4°C | 24.4°C |
| 9 September | 23.9°C | 23.7°C | 20.2°C | 24.7°C |
| 10 September | 24°C | 23.6°C | 20.2°C | 25.1°C |
| 11 September | 24.3°C | 23.4°C | 19.9°C | 24.9°C |
| 12 September | 24.4°C | 23.4°C | 19.9°C | 25.1°C |
| 13 September | 24.5°C | 23°C | 19.7°C | 26.4°C |
| 14 September | 23.8°C | 22.8°C | 19.7°C | 25.7°C |
| 15 September | 23.5°C | 22.8°C | 19.6°C | 25.5°C |
| Day | 2025 | 2024 | Min | Max |
|---|---|---|---|---|
| 16 September | 23.3°C | 22.6°C | 19.9°C | 25.3°C |
| 17 September | 23.2°C | 22.2°C | 20.1°C | 24.8°C |
| 18 September | 23.2°C | 22.2°C | 20°C | 24.4°C |
| 19 September | 22.8°C | 21.9°C | 19.8°C | 24.8°C |
| 20 September | 22.5°C | 21.7°C | 19.7°C | 24.5°C |
| 21 September | 22°C | 21.9°C | 19.6°C | 24.5°C |
| 22 September | 22°C | 21.4°C | 19.4°C | 24.4°C |
| 23 September | 21.6°C | 21.1°C | 19.4°C | 23.7°C |
| 24 September | 21.4°C | 21.4°C | 19.4°C | 23.2°C |
| 25 September | 21.4°C | 21.4°C | 19°C | 22.8°C |
| 26 September | 21.7°C | 21.4°C | 18.8°C | 22.5°C |
| 27 September | 21°C | 18.4°C | 23.3°C | |
| 28 September | 20.7°C | 18.3°C | 23.2°C | |
| 29 September | 20.9°C | 18.2°C | 22.6°C | |
| 30 September | 20.6°C | 18.5°C | 22.5°C |
Average water temperature in Otaru in September over a decade
| 2015 | 2016 | 2017 | 2018 | 2019 |
| 21°C | 21.8°C | 20.6°C | 20.5°C | 21.6°C |
| 2020 | 2021 | 2022 | 2023 | 2024 |
| 22.4°C | 21.3°C | 21.3°C | 23.6°C | 22.4°C |
Otaru sea state in September
Chart comparing the height of waves in Otaru in September over the past years. The red line indicates the height of the waves when swimming in the sea is prohibited. To view the current sea conditions, click on the graph.
Weather and climate in Otaru in September
This data display average monthly climate indicators in Otaru in September based on our historical weather readings over a period of ten years. In addition to temperature, we include data on the number of rainy and sunny days so you can have all the information about your destination before your trip
- Average HIGH temperature22°C
- Average LOW temperature14°C
- Average humidity
72 - Average rainfall days13 days
- Average rainfall4.9''/124mm
- Average sunshine5.5h
Otaru water temperature during other months:
You can also view information about water temperature for other months by clicking on the month button below
