Phu Quoc island is best visited between October to the end of April when rainy season is not yet in effect.
Peak season for foreign travelers typically occurs in December and Febuarary. From our experience, from May to July you can still enjoy your time in Phu Quoc with many sunny days in the South of Phu Quoc regardless of short-time rainy. Especially, Rainy season or summer time is also when the sea gets sandy beaches of islands in the An Thoi archipelago accreted, which makes the island more beautiful on sunny days.
Click to see details about the individual period for best sea activities.