Cat Hai, Vietnam offers 3 beaches perfect for sunbathing, surfing, swimming, and more. Cat Hai, Binh Dinh, Vietnam is known for its proximity to the stunning Ky Co Beach and the historical Champa ruins at Banh It Towers. The best time to travel to Cat Hai, Vietnam, is from October to April, with average air temperatures around 20-25°C (68-77°F) and water temperatures around 22-25°C (72-77°F). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!