An Hai, Vietnam offers 2 beaches perfect for sunbathing, surfing, swimming, and more. An Hai, Quang Ngai, Vietnam, is known for the My Lai Massacre Memorial Site. The best time to travel to An Hai, Vietnam, is from February to April, when the average air temperature is around 25-30°C (77-86°F) and the water temperature is approximately 26-28°C (79-82°F). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!