I booked a tour to the Similan Islands because I heard you can see beautiful, crystal-clear waters there! ★ In conclusion, it was absolutely fantastic!!! I was so touched by how kind all the tour guides were (;;)♡ They spoke to us Japanese people in Japanese, took wonderful photos for us (both on land and in the water), remembered our names and were so considerate—they were all wonderful people! It takes time to get there, but it was well worth it for the wonderful memories we made! Breakfast, lunch, water/juice and snacks were provided on the boat, and snacks were also provided after the tour, so you don't need to bring anything! On the way back, it was raining and the boat was quite bumpy, which surprised me, but we made it back safely 🙂↕️ I was fine, but if you're worried, it's a good idea to bring motion sickness medication! (I think you can also get some from the tour guides!)
Anonymous User
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Similan Island Weather, Climate and Best Time to Visit
Data source:Meteostat Update date:2025-09
Similan Island year round climate
Spring (March–May): Average 27.7–28.5°C, hot climate. March has almost no rainfall, while April and May see gradually increasing rainfall. Common activities: Scuba diving, snorkeling, sunbathing. Recommended clothing: Light, short-sleeved clothing, swimwear, sun protection clothing.
Summer (June–August): Average 27.1–27.6°C, hot and humid climate. June and August have more rainfall. Common activities: Scuba diving, snorkeling, but be aware of the rainy season's impact. Recommended clothing: Light and breathable short-sleeved clothing, swimwear, rain gear.
Autumn (September–November): Average 26.4–26.7°C, hot climate with heavier rainfall; September is the peak of the rainy season. Common activities: Scuba diving, snorkeling, but be aware of sea conditions and rainfall. Recommended clothing: Light and breathable short-sleeved clothing, rain gear.
Winter (December–February): Average 26.7–27.1°C, warm climate with less rainfall. Common activities: Scuba diving, snorkeling, sunbathing. Recommended clothing: Light short-sleeved clothing, swimwear.
Similan Island climatological average
Annual average temperature: approx. 27.2°C / Annual rainfall: approx. 2962 mm / Summer humidity: 75%–85% / Rainiest month: September
Similan Island monthly average temperature and precipitation
Month
Air temperature (°C)
Precipitation (mm)
January
26.8°C
49.1
February
27.1°C
171.3
March
27.7°C
0
April
28.5°C
40.1
May
28.1°C
445.6
June
27.6°C
578.5
July
27.1°C
0
August
27.1°C
373.6
September
26.4°C
611
October
26.4°C
287.1
November
26.7°C
292.3
December
26.7°C
113.9
Similan Island weather for the next seven days
6/15
Monday
Patchy rain nearby
29.9°C/26.5°C
6/16
Tuesday
Patchy rain nearby
29.7°C/26.6°C
6/17
Wednesday
Moderate rain
29.5°C/26.6°C
6/18
Thursday
Patchy rain nearby
29.5°C/26.4°C
6/19
Friday
Moderate rain
29.3°C/26.1°C
6/20
Saturday
Patchy rain nearby
27.9°C/25.8°C
6/21
Sunday
Patchy rain nearby
28.5°C/26.1°C
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