Harbor Beach, United States offers 3 beaches perfect for sunbathing, surfing, swimming, and more. Harbor Beach is known for the Harbor Beach Lighthouse and the world's largest man-made freshwater harbor. The best time to travel to Harbor Beach, United States, is during the summer months of June to August, when the average air temperature is around 70-80°F and the water temperature is approximately 60-70°F. Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!