Seacliff, Australia offers 3 beaches perfect for sunbathing, surfing, swimming, and more. Seacliff, South Australia, Australia, is known for its picturesque Seacliff Beach and the historic Seacliff Hotel. The best time to travel to Seacliff, Australia, is during the summer months of December to February, when the average air temperature is around 25°C (77°F) and the water temperature is approximately 21°C (70°F). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!