Birch Bay, United States offers 2 beaches perfect for sunbathing, surfing, swimming, and more. Birch Bay is known for Birch Bay State Park and its scenic waterfront views. The best time to travel to Birch Bay, United States, is during the summer months of July and August, when the average air temperature is around 70°F (21°C) and the water temperature is approximately 60°F (16°C). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!