Hat Sai Ri, Thailand offers 3 beaches perfect for sunbathing, surfing, swimming, and more. Hat Sai Ri, Chumphon, Thailand, is known for its beautiful beaches and the Prince of Chumphon Shrine. The best time to travel to Hat Sai Ri, Thailand, is from December to February, with average air temperatures around 27°C (81°F) and water temperatures about 28°C (82°F). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!