Koh Rok Yai, Thailand offers 1 beach perfect for sunbathing, surfing, swimming, and more. Koh Rok Yai, Krabi, Thailand, is known for its pristine beaches and vibrant coral reefs ideal for snorkeling and diving. The best time to visit Koh Rok Yai, Thailand, is from November to April, with average air temperatures around 28°C (82°F) and water temperatures near 29°C (84°F). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!