French Island, Australia offers 1 beach perfect for sunbathing, surfing, swimming, and more. French Island, Victoria, Australia, is known for the French Island National Park and its population of koalas. The best time to visit French Island, 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 18-20°C (64-68°F). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!