Middleborough, United States offers 1 beach perfect for sunbathing, surfing, swimming, and more. Middleborough, Massachusetts, United States, is known for the Oliver Mill Park and its historic 18th-century mill ruins. The best time to travel to Middleborough, United States, is in late spring (May to June) when the average air temperature is around 60-70°F and water temperature is approximately 50-60°F. Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!