Nga Man, Vietnam offers 1 beach perfect for sunbathing, surfing, swimming, and more. Nga Man, Quang Ngai, Vietnam, is known for the My Lai Massacre Memorial Site. The best time to travel to Nga Man, Vietnam, is from November to April, with average air temperatures around 70-85°F (21-29°C) and water temperatures around 75-82°F (24-28°C). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!