Lopa, United States offers 4 beaches perfect for sunbathing, surfing, swimming, and more. Lopa, Hawaii, United States, is known for its proximity to the pristine beaches and luxury resorts of Lanai. The best time to travel to Lopa, United States, is during the summer months when the average air temperature is around 75°F (24°C) and the water temperature is approximately 70°F (21°C). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!