Otsego Lake, United States offers 1 beach perfect for sunbathing, surfing, swimming, and more. Otsego Lake, Michigan, United States, is known for the Otsego Lake State Park, which offers scenic views and outdoor recreational activities. The best time to visit Otsego Lake, 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!