Late Spring through Early Summer. Watch Hill and Sailors Haven, accessible by private boat, passenger ferry, or on foot from nearby Fire Island communities, are open mid-May to mid-October. Early Summer through Labor Day. Watch Hill and Sailors Haven. Parts of Fire Island are accessible all year, but most people come during the summer months (late-June through September) when the weather is most favorable for beach related activities. In the off-season (October through April), public transportation to the island may be limited, and some services on various parts of the island are unavailable. Talisman/Barrett Beach.