Whitsunday Island, Australia offers 3 beaches perfect for sunbathing, surfing, swimming, and more. Whitsunday Island is known for Whitehaven Beach and the Great Barrier Reef. The best time to visit Whitsunday Island, Australia, is from May to September, when the average air temperature is around 23-26°C (73-79°F) and the water temperature is approximately 23°C (73°F). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!