Similan Island Weather

If you have not visited the Similan Islands, then you must. The Similan Islands offer the best diving waters of Thailand. You will not find such wonderful scuba diving as can be found in this national park. You will also enjoy the view along the way because the Simlan Islands are a chain of 9 tny and verdant islands with white sand beaches.
Every taste and budget is satisfied with these islands. You can choose from the lowest amount to a more luxury accommodation – both will give you memories to speak of for years. There is no substitute for a liveaboard. You can visit all 25 or so scattered sites at your leisure.
Rough and ready backpacking trip or a deluxe 5-star cruise, you choose and let nature take it’s course. Find what you want in our Similan Island liveaboards section. The trips range from a standard 4 night cruise to 9 or 10 night safaris that visit Burma too.
Enjoy more of the Similans by choosing one or more day trips from  Khao Lak or Phuket.  Although the journey times are greater (45 or 90 km away, respectively). This is recommended  if you are short on time or don't fancy staying on a boat for a few nights, then this may be the choice for you. You can also check out our day trip packages, which can be both with or without accommodation, in our Khao Lak day trip and Phuket day trip pages.

Diving Season

Liveaboards come alive from early November to early May. Enjoy a day trip and an overnight trip from October through to May. We have found that the most constant weather patterns, and therefore, the most stable conditions, tend to be between February and April.  Diving during this time of the year is a diver’s dream come true. The visiibility is always between 25-40m, and calm seas are the norm. The clouds even disappear during this time and all you see if blue. The Similans are only 8 degrees north of the Equator and therefore exhibit a tropical climate, including a water temperature that usually ranges between 26-29°C, being warmest towards the end of the season (February-May). Even at depth, the water is usually only 1 degree less than at the surface.  Imagine having good light conditions as you descend to depth – then that, during this time, is the Similan Islands.
As per our weather updates and tracking  the currents tend to be stronger towards the end of February. That means that drives dives will become more interesting and also attract more pelagics such as manta rays and whale sharks. Green and hawksbill turtles are often seen at the dive sites. Their breeding season is from November to February.

Constant diving can have some effects on an area. The dive sites for this area are closed for 6 months in order to allow mother nature to recuperate and be ready for your dive accordingly. This closed rainy season fortunately co-incides with a period of spawning for many of the fishes.