Big Stone Beach, United States offers 1 beach perfect for sunbathing, surfing, swimming, and more. Big Stone Beach, Delaware, United States, is known for its proximity to the Prime Hook National Wildlife Refuge. The best time to visit Big Stone Beach, United States, is during the summer months of June to August, when the average air temperature is around 75°F (24°C) and the water temperature is approximately 70°F (21°C). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!