To be honest scuba diving phuket is good all year round. Yes the are days when the sea is rougher or the sky cloudy. Again yes here in phuket thailand it does rain from time to time. We also can have big tropical storms too just like anywhere else in the tropics. However people have been scubadiving in phuket now for many years and the dive centers and experienced instructors know that no matter what the conditions above the water there is always fun to be had underwater. Many people will find the conditions scuba diving phuket far better than many locations they are used to compared to the conditions they are used to back home. In phuket scuba diving really is in a class of its own. Warm water 365 days a year with it never going below 26 degrees and mostly 28 -30 degrees for most of the year.
phuket thailand is blessed with its location as in reality the weather comes from the east for six months and then from the west for six months. This means that when in phuket scuba diving the dive sites are protected for months on end. We have dive sites that we use in high season and ones in low season. Most islands lie north south so as can just switch from one side to the other as the season changes which again means that each side of the island is free from divers and snorkelers for half the year and gives the locations plenty of time with no human interaction at all.
During “high” season the weather comes from the east which makes for flat seas and light winds as a rule. These conditions also mean that the similan island national park opens up some of the best diving on the planet. The similan islands lie to the north west of phuket offering 40 meter viz almost all the time. The similan islands are a fair distance so when scuba diving in phuket the best way is to join a similan liveaboard. These range from an overnight trip to eight days. The highlight for many is diving richelieu rock which is listed as one of the top 10 divesites of the world by National Geographic. The similan islands are open from 15th October each year and close again around the 15th of May.
The basic rules when in phuket scuba diving are from mid November till mid May the weather should be from the east and flat sea and blue sky. Then from mid May till mid November you can expect on a two week holiday a few days of rain. This does not really affect the diving too much but during the off season you get the odd tropical storm. This can cause the waves which can be not so good getting to and from the divesites. As mentioned before the sites themselves are sheltered but its getting between the islands that can be bumpy. The good thing is there are islands and other locations in very close for the dive trip to be cancelled is very rare.
phuket thailand is a great place to dive all year. Low season offers a much quieter time and the boats are half empty and many more shy creatures come out that have been scared off by the noise of high season but the sea may get bumpy for a few days and you may get some rain, but underwater you dont know its raining anyway as you are already wet. All it means is you cant use the sun deck between dives. High season is blue sky and flat sea but boats are full and the need to book well in advance is certain to get to the more popular locations. So if you are looking for a great scuba diving trip then low season in phuket thailand is great as the hotels are cheaper, the boats and dive sites quieter. After a days diving in phuket there are no crowded restaurants so you can eat when and where you like. Get a seat at the bar to watch a live band and a quiet beer or cocktail without getting swamped by 20 others all looking for the same seat. So as you can see scuba diving phuket in low or green season really is a good move and you can get in some great diving all year round.