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Koh Samui Weather in September

Thailand

September represents peak monsoon with warm temperatures near 28°C and the heaviest rainfall of the year, best suited for determined budget travelers and those interested in authentic quieter island experiences away from tourists.

Avg High

32°C

Avg Low

25°C

Daily Rain

5.5mm

Rainfall

Moderate

💡 Best months to visit Koh Samui: Feb, Mar, Jan

Koh Samui Weather by Month

Month	High	Low	Rain
Jan	29°C	24°C	3mm
Feb	30°C	24°C	1.5mm
Mar	31°C	25°C	2mm
Apr	33°C	26°C	2.5mm
May	33°C	26°C	5mm
Jun	32°C	26°C	4.5mm
Jul	32°C	25°C	5.5mm
Aug	32°C	25°C	5mm
Sep	32°C	25°C	5.5mm
Oct	31°C	25°C	10mm
Nov	30°C	25°C	13mm
Dec	29°C	24°C	6.5mm

About Koh Samui

This tropical island paradise features white-sand beaches, coconut palms, luxury resorts, nightlife and perfect-postcard island tranquility.

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