Sag Harbor, United States offers 4 beaches perfect for sunbathing, surfing, swimming, and more. Sag Harbor is known for its historic whaling museum, charming Main Street, and the iconic Sag Harbor Cinema. The best time to travel to Sag Harbor 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!