Similan Islands in July
Not the best time
Complete closure continues with dangerous weather conditions. Absolutely not recommended for any water activities - focus your Thailand trip elsewhere during this period.
Weather
Peak monsoon with relentless rainfall and stormy seas. Visibility drops to nearly zero underwater when tours occasionally run. Lightning storms are frequent and dangerous.
31°C high25°C low20 rain days
Crowds & Cost
low crowds
~$75/day average
Events & Festivals
- •Asahna Bucha Day
- •Buddhist Lent begins
July Tips
- •Islands remain closed by national park
- •Use this time to explore other regions
- •Mainland Khao Lak offers spa retreats and cultural experiences
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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