Hai Tan, Vietnam offers 2 beaches perfect for sunbathing, surfing, swimming, and more. Hai Tan, Quang Ngai, Vietnam, is known for the My Lai Massacre Memorial Site. The best time to travel to Hai Tan, Vietnam, is from December to April, with average air temperatures around 24-30°C (75-86°F) and water temperatures around 25-28°C (77-82°F). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!