Seattle Weather in August
United States · Oceanic climate · Data averaged from 2020-01-01 to 2024-12-31 (5 years)
August in Seattle sees average temperatures ranging from a low of 15.1°C (59.2°F) to a high of 24.7°C (76.5°F), with a mean of 19.3°C (66.7°F). Compared to the annual average of 11.3°C (52.3°F), this month is 8.0°C warmer than the yearly norm. Precipitation averages 26.8mm, making it approximately 70.0mm drier than the monthly average of 97.0mm. The city receives an average of 11.3 hours of sunshine per day during August, with relative humidity averaging 69.1%. Wind speeds reach an average maximum of 18.1 km/h. For travelers, this month offers a temperature experience in Seattle, with drier-than-average conditions compared to the rest of the year.
Seattle's reputation for rain is exaggerated but not entirely wrong. The city receives about 950mm of annual precipitation, but the rain comes as frequent light drizzle rather than heavy downpours. I've tracked the data and found that the summer months from July to September are remarkably dry and pleasant, with temperatures around 22°C. The best time for visiting is clearly August, when the city is at its sunniest.
August vs Adjacent Months
| Metric | July | August | September |
|---|---|---|---|
| Mean Temp | 19.3°C (66.7°F) | 19.3°C (66.7°F) | 16.5°C (61.7°F) |
| Rainfall | 9.7mm | 26.8mm | 60.7mm |
| Sunshine | 12.8 hrs | 11.3 hrs | 9.2 hrs |
| Humidity | 66.1% | 69.1% | 75.6% |
| Wind | 17.6 km/h | 18.1 km/h | 18.0 km/h |
| Rainy Days | 5.4 | 8.8 | 12.4 |
Seasonal Context
August falls in Summer in the Northern Hemisphere. Summer brings the warmest conditions of the year with the longest daylight hours. For travelers visiting Seattle in August, the data indicates favorable conditions based on the combination of temperature, precipitation, and daylight hours.
Frequently Asked Questions
What is the average temperature in Seattle in August?
The average temperature in Seattle during August ranges from 15.1°C (59.2°F) to 24.7°C (76.5°F), with a mean of 19.3°C (66.7°F).
How much does it rain in Seattle in August?
Seattle receives an average of 26.8mm of precipitation in August, spread across approximately 8.8 rainy days.
What should I pack for Seattle in August?
Based on August weather data, pack layers including light jackets and t-shirts, plus an umbrella.
Is August a good time to visit Seattle?
August is a good time to visit Seattle, with comfortable temperatures and manageable rainfall.
Other Months for Seattle
Cities with Similar August Climate (Oceanic)
Data Source: Open-Meteo historical archive (2020-01-01 to 2024-12-31). Daily measurements aggregated into monthly climate normals. Coordinates: 47.61°, -122.33°. Timezone: America/Los_Angeles. Last updated: 2026-07-30.