Water temperature in Bellevue (WA) in September
Is it warm enough to swim in Bellevue in September? Average water temperature in Bellevue in September is 63.1°F and therefore is not suitable for comfortable swimming. The warmest water in Bellevue in September is 75.2°F, and the coldest is 55.4°F. To find out the water temperature today and in the coming days, go to Current water temperature in Bellevue
Changes water temperature in Bellevue in September 2025, 2024
To get an accurate forecast for the water temperature in Bellevue for any chosen month, compare two years within a 10 year range using the chart below.
You can choose any other years:
| Day |
2025 |
2024 |
| September 1 | 68°F | 66.2°F |
| September 2 | 68°F | 66.2°F |
| September 3 | 68°F | 68°F |
| September 4 | 66.2°F | 68°F |
| September 5 | 66.2°F | 69.8°F |
| September 6 | 66.2°F | 69.8°F |
| September 7 | 66.2°F | 68°F |
| September 8 | 66.2°F | 68°F |
| September 9 | 64.4°F | 68°F |
| September 10 | 64.4°F | 66.2°F |
| September 11 | 64.4°F | 64.4°F |
| September 12 | 64.4°F | 62.6°F |
| September 13 | 62.6°F | 60.8°F |
| September 14 | 62.6°F | 60.8°F |
| September 15 | 64.4°F | 59°F |
| Day |
2025 |
2024 |
| September 16 | 64.4°F | 59°F |
| September 17 | 64.4°F | 59°F |
| September 18 | 64.4°F | 59°F |
| September 19 | 62.6°F | 59°F |
| September 20 | 62.6°F | 59°F |
| September 21 | 62.6°F | 59°F |
| September 22 | 60.8°F | 60.8°F |
| September 23 | 60.8°F | 60.8°F |
| September 24 | | 60.8°F |
| September 25 | | 60.8°F |
| September 26 | | 60.8°F |
| September 27 | | 60.8°F |
| September 28 | | 59°F |
| September 29 | | 57.2°F |
| September 30 | | 55.4°F |
Average water temperature in Bellevue in September over a decade
| 2015 | 2016 | 2017 | 2018 | 2019 |
| | 65.5°F | 61.3°F | 62.8°F |
| 2020 | 2021 | 2022 | 2023 | 2024 |
| 64.8°F | 61.3°F | 65.1°F | 62.1°F | 62.6°F |
Bellevue water temperature during other months:
You can also view information about water temperature for other months by clicking on the month button below
