Muara Upu, Indonesia offers 3 beaches perfect for sunbathing, surfing, swimming, and more. Muara Upu, North Sumatra, Indonesia, is known for its proximity to the stunning Lake Toba and the cultural heritage of the Batak people. The best time to travel to Muara Upu, Indonesia, is from May to September, with average air temperatures around 27°C (81°F) and water temperatures near 29°C (84°F). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!