Fort Pierre, United States offers 1 beach perfect for sunbathing, surfing, swimming, and more. Fort Pierre is known for the Verendrye Monument and the Casey Tibbs South Dakota Rodeo Center. The best time to travel to Fort Pierre, United States, is in late spring or early fall when the average air temperature is around 60-70°F, and the Missouri River water temperature is approximately 55-65°F. Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!