Shelltown, United States offers 1 beach perfect for sunbathing, surfing, swimming, and more. Shelltown, Maryland, United States, is known for the Chesapeake Bay and its proximity to the Assateague Island National Seashore. The best time to travel to Shelltown, United States, is during late spring when the average air temperature is around 70°F and the water temperature is approximately 65°F. Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!