Tonto Basin, United States offers 1 beach perfect for sunbathing, surfing, swimming, and more. Seabrook Island is known for its pristine beaches, the Seabrook Island Club, and the Bohicket Marina. The best time to travel to Tonto Basin, United States, is in late spring or early fall 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!