Sloping Main, Australia offers 1 beach perfect for sunbathing, surfing, swimming, and more. Sloping Main, Tasmania, Australia, is known for its proximity to the Tasman National Park and the Port Arthur Historic Site. The best time to travel to Sloping Main, Australia, is during the summer months of December to February, when the average air temperature is around 20-25°C (68-77°F) and the water temperature is approximately 18-21°C (64-70°F). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!