Coupeville, United States offers 17 beaches perfect for sunbathing, surfing, swimming, and more. Coupeville, Washington, United States, is known for its historic waterfront district and proximity to Ebey's Landing National Historical Reserve. The best time to travel to Coupeville, United States, is from June to September, when the average air temperature is around 60-70°F and the water temperature is approximately 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!