Mua, Tonga offers 3 beaches perfect for sunbathing, surfing, swimming, and more. Mua, Tongatapu, Tonga, is known for the ancient archaeological site of Ha'amonga 'a Maui. The best time to travel to Mua, Tonga, is from May to October, with average air temperatures around 24-28°C (75-82°F) and water temperatures approximately 25-27°C (77-81°F). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!