Niantic, United States offers 3 beaches perfect for sunbathing, surfing, swimming, and more. Niantic, Connecticut, United States, is known for Rocky Neck State Park and the Niantic Bay Boardwalk. The best time to travel to Niantic, 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!