Similan Islands in May
Not the best time
Hit-or-miss weather makes this a gamble. Some operators close entirely while others offer significantly discounted rates for the brave few willing to risk rough seas.
Weather
Monsoon transition month brings unpredictable weather patterns. Some days are scorching hot, others see sudden downpours. Seas start getting choppy with increasing southwest winds.
33°C high26°C low12 rain days
Crowds & Cost
moderate crowds
~$120/day average
Events & Festivals
- •Vesak Day celebrations
- •Royal Ploughing Ceremony (Bangkok - affects domestic travel)
May Tips
- •Many dive operators close for the season by mid-May
- •Book flexible cancellation policies
- •Consider this month only if you have backup plans
All Months
The islands close completely from May 15 to October 15 due to monsoon conditions. Your window runs November through April, with distinct seasons within that period. November and December offer the calmest seas and best visibility for diving - often 35-40 meters. But expect higher prices and crowds, especially around Christmas. January through March delivers the most reliable weather with minimal rain and gentle breezes. This is peak season, so book accommodations and liveaboards well ahead. April sees rising temperatures (35°C daily) and occasional afternoon storms, but fewer crowds and better deals. The shoulder months of late October and early May can be spectacular if weather cooperates, but you're gambling on conditions. Water temperature stays warm year-round at 27-29°C. Northeast monsoon winds from December to February can make some dive sites choppy, but generally create better visibility.
Similan Islands Scores
Solo
7/10
Couples
8/10
Families
6/10
Adventure
9/10
Budget
5/10
Luxury
7/10
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