San Juan Island National Historical Park in August
August at San Juan Island National Historical Park averages a daytime high near 73°F and an overnight low around 50°F, with about 0.7" of precipitation. Visitation runs about 1.7× the park's average month, which makes August a very busy month here.
- Average low
- 50°F
- Average high
- 73°F
Range across the year: 37°F to 73°F
- Precipitation
- 0.7 in
- Daylight
- 14.1 hours
Roughly 14% of the park's yearly visitors come in August: about 58,000 recreation visits in a typical year, based on National Park Service monthly counts from 1979 to 2025.
That makes August the 2nd-busiest of the park's twelve months, sitting between the July peak (1.8×) and the January low (0.5×).
On our Best Time to Visit score August rates 53/100 ("Fair"). Our recommended month is October: the lightest crowds of the park's good-weather months.
The daily average of about 62°F is a comfortable range for hiking and being outdoors all day. These figures are 1991–2020 NOAA climate normals from the nearest station, about 1.7 miles from the park.
August falls inside the park's busiest stretch: June, July and August together pull about 42% of the year's visitors, so a visit this month means sharing the park with the peak-season crowd.
You'll have about 14.1 hours of daylight in August to explore — between the 8.1-hour midwinter low and the 15.9-hour summer high.
Park-wide, 2025 drew 420,922 recreation visits, up 3.7% from 405,925 in 2024.
Across the past decade overall visitation has risen about 68.5%, so a August visit is likely to feel busier than it did a few years ago.
How August compares with the months around it
| Month | Avg high / low | Crowds | Best-time score |
|---|---|---|---|
| July | 72°F / 50°F | 1.8× Very busy | 51 Fair |
| August | 73°F / 50°F | 1.7× Very busy | 53 Fair |
| September | 68°F / 48°F | 1.4× Busy | 54 Fair |
All twelve months at San Juan Island, with the best time to visit.
Things to do at San Juan Island in August
The National Park Service tags 8 San Juan Island activities for summer. Each links to the park's own page for it.
Frequently Asked Questions
August averages a daytime high near 73°F and an overnight low around 50°F at San Juan Island National Historical Park, with about 0.7 inches of precipitation. These are 1991–2020 NOAA climate normals from the nearest station, about 1.7 miles from the park, so conditions inside the park can differ, especially at other elevations.
August is very busy at San Juan Island National Historical Park (about 1.7× the average month). Our best-time score rates it "Fair" at 53/100. Our recommended month is October.
The busiest month is July and the quietest is January. August sits at about 1.7× the park's average, or 14% of annual visitation.
A typical August sees about 58,000 recreation visits at San Juan Island National Historical Park, based on National Park Service monthly counts from 1979–2025.
Where to stay near San Juan Island in August
Booking a August trip to San Juan Island National Historical Park? Compare hotels, cabins and vacation rentals near the park with live August availability and prices.
Top-rated places to stay near San Juan Island
Prices for Oct 30–Nov 1, 4 adults. Change dates on the map below.
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See the full ranking of the best national parks to visit in August.
Source: National Park Service Visitor Use Statistics (1979–2025), NOAA NCEI Climate Normals 1991–2020. Updated 2026-10-11.