Cranberry Isles, United States offers 1 beach perfect for sunbathing, surfing, swimming, and more. Cranberry Isles is known for its picturesque landscapes and the historic Great Cranberry Island Historical Society. The best time to travel to Cranberry Isles, United States, is during the summer months of July and August, when the average air temperature is around 70°F (21°C) and the water temperature is approximately 60°F (16°C). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!