Hoi An has generally two seasons: the dry season, that starts from around March until October and the raining season, from October till the end of February.
Dry season – Diving season:
This is the hot time of the year and also the only time to enjoy a snorkeling or diving trip to Cham Island. The weather can reach up to 40°C in July and August and the water temperature of the ocean is about 29°C. It is hot and humid in town, that is one of the reasons the locals get up early in the morning and have a long “siesta” at lunch time.
Wet season – no diving:
Usually around September there can be Typhoons. However the rain starts around October, said so in recent years it keeps changing. Some yeas we have 1-2 month of rain, misty weather and the temperature drops to about 17°C. Other years we hardly have rain at all and spend Christmas at the beach.
The ocean temperature during this time of the year drops to about 19°C and the tour boats are not going out due to the rough sea. Often we experience flooding in Hoi An in October or November.