Search for cities, countries, lakes and rivers
Sea Temperature in Seattle in September
Complete information on the sea temperature range in the Salish Sea in Seattle in September. Historical daily data. Climate details for September. Tips on swimming conditions and beach relaxation in Seattle. We find every spot where you can swim and tell you what the water temperature is there today and throughout the year.
Water Temperature Range in Seattle in September
50°F
MINIMUN
55°F
AVERAGE
59°F
MAXIMUM
Historical Data of Water Temperature in September in Seattle
Water Temperature Chart for Salish Sea in Seattle in September
Sea Temperature Table in Seattle in September Over the Past Years
| Day | 2024 | 2023 | 2022 | Average |
|---|---|---|---|---|
| Sep 1 | 54°C | 55°C | 57°C | 55°C |
| Sep 2 | 54°C | 55°C | 52°C | 54°C |
| Sep 3 | 55°C | 55°C | 52°C | 55°C |
| Sep 4 | 55°C | 55°C | 52°C | 54°C |
| Sep 5 | 55°C | 55°C | 57°C | 56°C |
| Sep 6 | 55°C | 55°C | 57°C | 56°C |
| Sep 7 | 55°C | 55°C | 59°C | 56°C |
| Sep 8 | 54°C | 55°C | 54°C | 55°C |
| Sep 9 | 55°C | 55°C | 55°C | 55°C |
| Sep 10 | 54°C | 55°C | 55°C | 55°C |
| Sep 11 | 54°C | 55°C | 52°C | 54°C |
| Sep 12 | 54°C | 57°C | 57°C | 55°C |
| Sep 13 | 55°C | 57°C | 55°C | 55°C |
| Sep 14 | 54°C | 57°C | 54°C | 55°C |
| Sep 15 | 55°C | 57°C | 55°C | 56°C |
| Sep 16 | 55°C | 59°C | 57°C | 57°C |
| Sep 17 | 54°C | 57°C | 52°C | 54°C |
| Sep 18 | 54°C | 59°C | 59°C | 56°C |
| Sep 19 | 55°C | 55°C | 54°C | 55°C |
| Sep 20 | 55°C | 55°C | 59°C | 56°C |
| Sep 21 | 54°C | 55°C | 54°C | 54°C |
| Sep 22 | 54°C | 57°C | 59°C | 55°C |
| Sep 23 | 54°C | 55°C | 54°C | 54°C |
| Sep 24 | 55°C | 57°C | 57°C | 56°C |
| Sep 25 | 54°C | 55°C | 52°C | 53°C |
| Sep 26 | 55°C | 55°C | 57°C | 55°C |
| Sep 27 | 54°C | 55°C | 59°C | 55°C |
| Sep 28 | 54°C | 55°C | 59°C | 55°C |
| Sep 29 | 54°C | 55°C | 54°C | 53°C |
Seattle Climate and Swimming Opportunities in September
72°F
Average Day Air Temperature
50°F
Average Night Air Temperature
2 in
Precipitation Amount per Month
9 days
Number of Rainy Days
12 hrs
Daylight
per Day
7 hrs
Sunshine
per Day
6 mph
Average Wind Speed
74%
Average
humidity
Seattle lies within the Washington in United States. The average daytime temperature in Seattle in September is 71°F (22°C), while the nighttime average is 51°F (10°C). There are typically nine rainy days during the month, with a total precipitation of 1.6 inches (41 mm). The daylight duration in September in Seattle is 12 hours, with an average of 7 hours of sunshine per day. The average wind speed in September is 6 mph (10 km/h), and the humidity level is around 74%.
The water temperature in Seattle in September ranges from 52°F to 55°F (11°C to 13°C). At the beginning of the month, the average temperature is around 55°F (13°C), shifting to 55°F (13°C) by mid-September and reaching 55°F (13°C) in the last ten days. Overall, the average sea temperature in Seattle for September is 55°F (13°C). The contrast between cool water and warm air makes for a refreshing swim. A great choice for those who enjoy invigorating dips.
Sea Temperature in September in Nearby Cities
Frequently Asked Questions About Water Temperatures in September in Seattle
What is the sea temperature in Seattle in September?
The water temperature in the Salish Sea in Seattle in September ranges from 52°F to 55°F (11°C to 13°C).
Is it possible to swim in the Salish Sea in Seattle in September?
The average sea temperature in Seattle in September is 55°F (13°C), and the air temperature is 71°F (22°C), so the contrast between cool water and warm air makes for a refreshing swim. A great choice for those who enjoy invigorating dips.