Best time to visit San Juan Island National Historical Park
June, August and September are the best balance at San Juan Island National Historical Park: mild and dry for the park (average highs 66° to 70°F), with crowds from busy to very busy. July is busiest, with about 69,000 visitors. November is the quietest, with highs near 54°F.
- Quiet
- Moderate
- Busy
- Very busy
- Few or no visits (may be closed)
- Best months
Month by month
- Station
- Whidbey Island Nas, WA USW00024255
- Lat / lon
- 48.35, -122.67
- Elevation
- 47 ft
- From park center
- 17.5 mi
- Normals
- 1991–2020
- Visits
- 2023–2025
| Field | Jan | Feb | Mar | Apr | May | Junbest | Jul | Augbest | Sepbest | Oct | Nov | Dec | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| High, °F | 49° | 51° | 55° | 58° | 62° | 66° | 69° | 70° | 67° | 60° | 54° | 49° | 59° |
| Low, °F | 38° | 37° | 40° | 43° | 48° | 52° | 54° | 54° | 50° | 46° | 41° | 38° | 45° |
| Precipitation, in | 2.4 | 1.6 | 1.7 | 1.7 | 1.7 | 1.1 | 0.6 | 0.8 | 1.1 | 2.0 | 3.1 | 1.9 | 19.9 |
| Snow, in | 1.1 | 1.0 | 0.6 | 0 | 0 | 0 | 0 | 0 | 0 | 0 | 0.3 | 2.4 | 5.4 |
| Daylight, h:mm | 8:43 | 10:06 | 11:44 | 13:36 | 15:11 | 16:05 | 15:44 | 14:20 | 12:31 | 10:43 | 9:08 | 8:20 | |
| Visitors, thousands | 20 | 18 | 28 | 32 | 44 | 56 | 69 | 62 | 47 | 17 | 16 | 18 | 428 |
| Crowds | Quiet | Quiet | Moderate | Moderate | Busy | Very busy | Very busy | Very busy | Busy | Quiet | Quiet | Quiet | |
| Weather | Cool | Cool | Cool | Mild, wet | Mild, wet | Mild | Mild | Mild | Mild | Mild, wet | Cool | Cool |
| Month | High °F | Low °F | Precip., in | Snow, in | Daylight | Visitors | Crowds | Weather |
|---|---|---|---|---|---|---|---|---|
| January | 49° | 38° | 2.4 | 1.1 | 8:43 | 20,000 | Quiet | Cool |
| February | 51° | 37° | 1.6 | 1.0 | 10:06 | 18,000 | Quiet | Cool |
| March | 55° | 40° | 1.7 | 0.6 | 11:44 | 28,000 | Moderate | Cool |
| April | 58° | 43° | 1.7 | 0 | 13:36 | 32,000 | Moderate | Mild, wet |
| May | 62° | 48° | 1.7 | 0 | 15:11 | 44,000 | Busy | Mild, wet |
| Junebest | 66° | 52° | 1.1 | 0 | 16:05 | 56,000 | Very busy | Mild |
| July | 69° | 54° | 0.6 | 0 | 15:44 | 69,000 | Very busy | Mild |
| Augustbest | 70° | 54° | 0.8 | 0 | 14:20 | 62,000 | Very busy | Mild |
| Septemberbest | 67° | 50° | 1.1 | 0 | 12:31 | 47,000 | Busy | Mild |
| October | 60° | 46° | 2.0 | 0 | 10:43 | 17,000 | Quiet | Mild, wet |
| November | 54° | 41° | 3.1 | 0.3 | 9:08 | 16,000 | Quiet | Cool |
| December | 49° | 38° | 1.9 | 2.4 | 8:20 | 18,000 | Quiet | Cool |
| Year | 59° | 45° | 19.9 | 5.4 | 428,000 | |||
Year: average high and low, total precipitation and snowfall, total visitors. T = trace (under 0.05 in). – = not measured at this station. Updated .
- Hottest August, average high 70°F
- Coldest nights February, average low 37°F
- Source NOAA National Centers for Environmental Information; National Park Service
- Visitors a year about 428,000 (2023–2025 average)
- State Washington
Closures, reservations and alerts: San Juan Island National Historical Park on nps.gov
Nearby
- Olympic National ParkBest: Apr, May and Jun · Washington
- North Cascades National ParkBest: May, Jun and Sep · Washington
- Ross Lake National Recreation AreaBest: Apr, May and Aug · Washington
- Mount Rainier National ParkBest: Jul, Aug and Sep · Washington