Swimming in Seattle in september 2025: Average sea temperature in september and tide times in september 2025
Average sea temperature in Seattle in september 2025.
In september, according to seasonal norms, the sea temperature in Seattle is:
Minimum: 52°F
Average: 54°F
Maximum: 56°F
Other useful seasonal weather averages in september:
- Outside temperature: 57°F to 73°F
- Most common weather: "Clear/Sunny"
- The wind blows at 8.7mph
- It rains a total of 1.4in, over 2 day(s).
Should we swim in Seattle in september?
No... The water temperature in Seattle in september is freezing
You won't be able to swim in Seattle in september! The water temperature is freezing, reaching as low as 52°F (and only 56°F at best)! Our advice: if you are going to Seattle this month, plan to sightsee and forget the beach!
Note also that in september, the climate is perfect with an average outside temperature of 65°F, 1.3in of precipitation (over 2 days) and 83.5 % humidity.
Water and normal seasonal temperatures in Seattle in september
| September | |||
| Average sea temperature | 54°F | ||
| Minimum sea temperature | 52°F | ||
| Maximum sea temperature | 56°F | ||
| Average outside temperature | 67°F | ||
| Maximum outside temperature | 74°F | ||
| Minimum outside temperature | 58°F | ||
| Wind speed | 6.2mph | ||
| Wind temperature | 58°F | ||
| Precipitation | 1.4in | ||
| Number of days of rain | 2 jour(s) (7%) | ||
| Humidity | 84% | ||
| Visibility in kilometers | 9.1km | ||
| Cloud cover | 32% | ||
| Our opinion | freezing swimming |
Chart of the tides in september 2025
Tide times in september 2025 in Seattle
Swim elsewhere in the United States (USA) in september
Swim in the United States (USA) in september: sea temperature by city