Water temperature in Seattle (WA) in May
Is it warm enough to swim in Seattle in May? Average water temperature in Seattle in May is 52°F and therefore is not suitable for comfortable swimming. The warmest sea in Seattle in May is 57.6°F, and the coldest is 48°F. Average high air temperature in Seattle in May is 65°F, and average low temperature is 47°F. To find out the sea temperature today and in the coming days, go to Current sea temperature in Seattle
Changes water temperature in Seattle in May 2025, 2024
To get an accurate forecast for the water temperature in Seattle for any chosen month, compare two years within a 10 year range using the chart below. In addition to the sea water temperature in Seattle, the selected years in the table also show the values of the maximum and minimum temperatures on each of the days of May.
You can choose any other years:
| Day | 2025 | 2024 | Min | Max |
|---|---|---|---|---|
| May 1 | 50.9°F | 50.5°F | 48°F | 54.5°F |
| May 2 | 51.1°F | 51.1°F | 48.2°F | 55.6°F |
| May 3 | 51.4°F | 51.6°F | 48°F | 56.8°F |
| May 4 | 52°F | 51.6°F | 48.2°F | 55.9°F |
| May 5 | 52.2°F | 51.3°F | 48.2°F | 55.4°F |
| May 6 | 52.3°F | 51.6°F | 48.2°F | 55.6°F |
| May 7 | 52.7°F | 51.3°F | 48.2°F | 55°F |
| May 8 | 52.7°F | 50.7°F | 48.2°F | 54.9°F |
| May 9 | 53.1°F | 51.4°F | 48.4°F | 54.5°F |
| May 10 | 52.9°F | 51.8°F | 48.7°F | 54.3°F |
| May 11 | 52.3°F | 52.5°F | 48.7°F | 55.6°F |
| May 12 | 52.3°F | 53.1°F | 48.7°F | 55.6°F |
| May 13 | 52.7°F | 53.2°F | 48.7°F | 56.5°F |
| May 14 | 52.5°F | 53.4°F | 48.7°F | 57°F |
| May 15 | 52.7°F | 52.7°F | 49.1°F | 56.7°F |
| Day | 2025 | 2024 | Min | Max |
|---|---|---|---|---|
| May 16 | 52.7°F | 53.1°F | 49.3°F | 56.7°F |
| May 17 | 52.5°F | 53.6°F | 49.5°F | 56.3°F |
| May 18 | 52.7°F | 53.2°F | 48.6°F | 57.6°F |
| May 19 | 51.6°F | 52.9°F | 50.2°F | 57.2°F |
| May 20 | 52°F | 53.6°F | 50.4°F | 55.9°F |
| May 21 | 52.3°F | 53.8°F | 50.7°F | 55.4°F |
| May 22 | 53.4°F | 54°F | 50.9°F | 55.4°F |
| May 23 | 52.5°F | 52.7°F | 50.7°F | 55.2°F |
| May 24 | 53.6°F | 52.9°F | 50.7°F | 55.9°F |
| May 25 | 53.2°F | 51.8°F | 50.5°F | 55.8°F |
| May 26 | 54.1°F | 51.8°F | 50.5°F | 55.9°F |
| May 27 | 54.3°F | 52.2°F | 50.2°F | 56.5°F |
| May 28 | 54.9°F | 51.8°F | 50°F | 57°F |
| May 29 | 53.6°F | 51.8°F | 49.6°F | 57.4°F |
| May 30 | 53.2°F | 51.8°F | 49.8°F | 56.1°F |
| May 31 | 53.6°F | 53.4°F | 49.8°F | 57°F |
Average water temperature in Seattle in May over a decade
| 2016 | 2017 | 2018 | 2019 | 2020 |
| 55°F | 52.5°F | 54.3°F | 53.4°F | 52.9°F |
| 2021 | 2022 | 2023 | 2024 | 2025 |
| 52.9°F | 51.4°F | 54.3°F | 52.3°F | 52.7°F |
Seattle sea state in May
Chart comparing the height of waves in Seattle in May 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 Seattle in May
This data display average monthly climate indicators in Seattle in May 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 temperature65°F
- Average LOW temperature47°F
- Average humidity
69 - Average rainfall days12 days
- Average rainfall48mm/1.9''
- Average daylight15h
- Average sunshine8.2h
- Average UV index6
Seattle water temperature during other months:
You can also view information about water temperature for other months by clicking on the month button below
