West Java, East Java, Central Java, Bali, Sumatra. Java Island is relatively more stable in its climate because it is near the equator. The peak mangosteen harvest season is during the wet season. Indonesian mangosteen's production level and export volume are the highest from January to March. Although mangosteen from Indonesia does not face direct competition with mangosteen from Thailand, the world's largest mangosteen supplier, there is little competition from April to August (high season of Thai mangosteen).