Ko Phet, Thailand offers 2 beaches perfect for sunbathing, surfing, swimming, and more. Ko Phet, Nakhon Si Thammarat, Thailand, is known for its proximity to the stunning Khao Luang National Park. The best time to travel to Ko Phet, Thailand, is between November and February, when the average air temperature is around 77-86°F (25-30°C) and the water temperature is approximately 82°F (28°C). Sandee provides detailed maps, photos, and reviews from fellow beachgoers to help you Choose Your Beach™ and plan your perfect beach vacation!