Waimanalo, United States offers 4 beaches perfect for sunbathing, surfing, swimming, and more. Waimanalo, Hawaii, United States, is known for its stunning Waimanalo Beach and the nearby Sea Life Park Hawaii. The best time to travel to Waimanalo, United States, is from April to October, with average air temperatures around 75-85°F and water temperatures ranging from 75-80°F. Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!