Ko Pha Ngan
Ko Pha Ngan (เกาะพะง้น, pronounced goh pa-ngan ง (ng) is a consonant without a separate G sound) is an island off the Central Gulf Coast of Southern Thailand forming part of the Chumphon Archipelago. Located halfway between the islands of Ko Samui and Ko Tao it is known as a land of coconut trees and the world (in)famous full moon parties.
The best time to visit the island and also high season is during December-March when the water is high, clean, and good for swimming. It's also not rainy and temperatures are pleasant. Another high season time is during July/August after dry season when the water is rising. Avoid visiting the island during dry season, Apr-Jun, when all of the best beaches on the northwest coast (Mae Haad, Haad Yao, Chalok Lam, Haad Khom) are useless for swimming due to shallow water. Swimming in this season is possible only on the north coast on beautiful Bottle Beach , less accessible east coast (Thong Nai Pan, Haad Sadet, Haad Rin), where the only beach with good access and swimming is Haad Rin, which is not as crowded at this time. The south coast should be avoided all year due to bad water and sand.