Posey Island
About
Posey Island is a 1-acre state park in Washington, managed by the state park agency. The nearest town is Roche Harbor, about 2 miles away. Summer is the most comfortable time to visit. Typical averages from the nearby Friday Harbor airport weather station show July and August highs in the low 70s with only six to eight wet days a month, while winter months bring highs in the upper 40s and rain on about half the days. Several trails lie within a few miles, including Westcott Bay Trail at about 2 miles and Bell Point Trail at about 2.3 miles. For an overnight stay, the Cascadia Marine Trail Campsite on Stuart Island is about 4.4 miles away, and D'Arcy Island Campground on the BC Marine Trail is about 6 miles away.
Park size
1 acres
Location
Posey Island
Washington
Data source: USGS PAD-US 4.1 (Protected Areas Database, public domain)
Facts about this place
When to go
Best time to go: May–Sep. The mildest months here, with typical highs of 64–73°F and lows of 44–50°F.
Typical monthly averages (not a forecast) from the Friday Harbor Ap, WA weather station, 9.4 mi away. High / low in °F.
- Jan47° high37° low
- Feb48° high36° low
- Mar53° high38° low
- Apr57° high41° low
- May64° high44° low
- Jun68° high48° low
- Jul72° high50° low
- Aug73° high50° low
- Sep68° high48° low
- Oct58° high44° low
- Nov51° high40° low
- Dec46° high37° low
Where it is
- Posey Island · State park
- Nearest town
- Roche Harbor, Washington · 1.9 mi
- Managed by
- State Park and Recreation
Nearby
- Westcott Bay TrailHiking2 mi
- Bell Point TrailHiking2.3 mi
- Officer's QuartersHiking2.5 mi
- Young Hill TrailHiking2.7 mi
- Cascadia Marine Trail Campsite - Stuart IslandCamping4.4 mi
- Cascadia Marine Trail Campsite for human powered boatersCamping5.3 mi
- D'Arcy Island Campground / BC Marine TrailCamping6 mi
- Sidney Spit Campsite / BC Marine TrailCamping7.4 mi
Source: Roamze catalog (indexable pages within 10 miles, PostGIS distance)
Best time to visit Posey Island
Best months: April–September. Best months have typical highs of 55–85 °F, lows of 30 °F or warmer (32 °F where the station doesn't record snow), at most one snowy day and no more than 12 wet days.
Jan
47° / 37°
16 wet
Feb
48° / 36°
14 wet
Mar
53° / 38°
14 wet
Apr
57° / 41°
11 wet
May
64° / 44°
9 wet
Jun
68° / 48°
7 wet
Jul
72° / 50°
6 wet
Aug
73° / 50°
8 wet
Sep
68° / 48°
12 wet
Oct
58° / 44°
15 wet
Nov
51° / 40°
16 wet
Dec
46° / 37°
16 wet
Typical high / low (°F) and days with rain or snow, 1991–2020. Measured at Friday Harbor Ap, WA, 9.4 mi away at 109 ft. We don't have this place's elevation, so higher spots nearby can run cooler. This station doesn't record snowfall. Source: NOAA NCEI U.S. Climate Normals 1991–2020.
