Weather in Seattle in August 2025
- August is usually the hottest month of the year in Seattle;
Average weather
Average temperature in Seattle in August
Going from a maximum of +91°F during the day to a minimum of +55°F during the night, the temperature in August averages around +81°F.
The average maximum temperature goes down 20% by the end of the month, compared with the beginning of the month, from +79°F to +72°F.
Is Seattle warm or cold in August?
Seattle is typically warm in August.
Maximum temperatures go up compared to the previous month from +75°F to +75°F. The minimum temperature also goes up from +57°F to +57°F.
It’s generally warm, but pack a long-sleeve shirt for evenings.
August is the hottest month in Seattle, here is the comparison with other months:
Water temperature in Seattle in August
Water in Seattle in August is Cold. It varies from +51°F to +55°F, with an average of +53°F. The air temperature averaging +75°F is higher than the water temperature.
The water temperature in August is one of the warmest of the entire year:
Can you swim in Seattle in August?
Travel to Seattle
Climate in Seattle in August
| July | August | September | ||||
|---|---|---|---|---|---|---|
| Avg. temperature | ||||||
| +75°F | +75°F | +70°F | ||||
| Min. temperature | ||||||
| +48°F | +46°F | +41°F | ||||
| Max. temperature | ||||||
| +95°F | +97°F | +91°F | ||||
| Rainfall | ||||||
| 28 mm | 29 mm | 62 mm | ||||
| Wind | ||||||
| 1 m/s | 1 m/s | 1 m/s | ||||
| Avg. water temperature | ||||||
| +51°F | +53°F | +53°F | ||||
| Humidity | ||||||
| 70% | 71% | 76% | ||||
| Air pressure | ||||||
| 1016 HPa | 1015 HPa | 1015 HPa | ||||
| Sunny days | ||||||
| 10 | 9 | 7 | ||||
| Cloudy days | ||||||
| 12 | 13 | 10 | ||||
| Rainy days | ||||||
| 9 | 9 | 13 | ||||
| Snowy days | ||||||
| 0 | 0 | 0 | ||||
August weather is still as good as in July. The temperature levels stay the same in the area of +75°F for average maximum temperature during the day. Prepare for more rain. Average rainfall goes from 28 mm to 29 mm. Humidity rises from 70% to 71%. The average wind speed doesn’t change much during August, staying around 1 m/s. The days becoming less sunny, going from 10 sunny days in July to 9 in August.
Next month (September) brings a further decline in the weather.
Wind
The average wind speed is 1 m/s getting up to 2 m/s which is a light breeze; barely moving the tree leaves.
The average wind speed in Seattle is gradually increasing during August, going from 1 m/s to 1 m/s over the course of the month.
Rain
How was the weather last August in Seattle?
Climate Change Over the Years
The climate in Seattle in August has not changed that much over the last 43 years.
The average temperature was the lowest in 2011 (+57°F) and the highest in 2014 (+62°F). The driest year was 1985 with only 714 mm of rainfall, and the wettest year was 2021 with 2549 mm.
FAQ
Is August a good time to visit Seattle?
Can you sunbathe in Seattle in August?
Can you swim in Seattle in August?
Is Seattle rainy in August?
Is it sunny in Seattle in August?
How much does it cost to fly to Seattle in August?
Other cities in USA
Monthly weather in Seattle
Source of the data
For this page, we’ve looked at the typical weather in Seattle, based on historical hourly weather data from January 1, 1979, to December 31, 2023.
For past dates, we show actual recorded data at the location at that time. Forecasts are based on recorded weather during that day of the year, averaged over the total years for which we have records (unless stated otherwise). The daily temperature is the highest recorded temperature in the shadow during that day.