Friday Harbor, United States offers 21 beaches perfect for sunbathing, surfing, swimming, and more. Friday Harbor is known for the San Juan Islands, Whale Museum, and Lime Kiln Point State Park. The best time to visit Friday Harbor is from June to September, with average air temperatures around 60-70°F and water temperatures around 50-55°F. Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!