Llanthadiya, Sri Lanka offers 5 beaches perfect for sunbathing, surfing, swimming, and more. Llanthadiya, North Western Province, Sri Lanka, is known for the Wilpattu National Park. The best time to travel to Llanthadiya, Sri Lanka, is from December to March, with average air temperatures around 27°C (81°F) and water temperatures near 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!