San Juan Island National Historical Park: Alerts, Map, Weather & Trailie Planner

About San Juan Island National Historical Park

San Juan Island is well known for its splendid vistas, saltwater shores, quiet woodlands, orca whales and one of the last remaining native prairies in the Puget Sound/Northern Straits region. But it was also here in 1859 that the United States and Great Britain nearly went to war over possession of the island, the crisis ignited by the death of a pig.

1 current NPS alert

Caution: Wildlife Viewing Guidelines

Source: National Park Service (as of Nov 1, 2026). Official San Juan Island National Historical Park page on nps.gov

Weather Information

Spring
Temperatures usually range from 40 F to 60 F.
Summer
Temperatures usually range from 45 F to 70 F.
Fall
Temperatures usually range from 40 F to 65 F.
Winter
Temperatures range from 35 F to 50 F.

Wildflowers are at their peak around May. On very sunny days, be prepared with water-heat exhaustion is a common complaint among park visitors who are unprepared. Rain is common. Be prepared with cold and wet weather gear and numerous layers if you intend to be outside. Rain and wind are common.

Operating Hours

Park grounds are open 24 hours per-day, year-round.

MondayAll Day
TuesdayAll Day
WednesdayAll Day
ThursdayAll Day
FridayAll Day
SaturdayAll Day
SundayAll Day

Planning San Juan Island National Historical Park

The summary above covers timing and highlights. These go deeper on reservations, crowds, and logistics — check Alerts for live updates.

Reservation rules vary by season and activity for San Juan Island. See Overview on this page for fees, timed entry, and campground details before you travel.