Custer, United States offers 2 beaches perfect for sunbathing, surfing, swimming, and more. Custer is known for the Crazy Horse Memorial and Custer State Park. The best time to travel to Custer, United States, is from June to August, with average air temperatures around 70-80°F and water temperatures in nearby lakes around 60-70°F. Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!