Hirogawa, Japan offers 2 beaches perfect for sunbathing, surfing, swimming, and more. Hirogawa is known for the Hirogawa River and its historical significance in flood control efforts. The best time to travel to Hirogawa, Japan, is in April when the average air temperature is around 15°C (59°F) and the water temperature is approximately 16°C (61°F). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!