Best in Thailand Koh Samui: Island in Thailand
Koh Samui is an island in the Gulf of Thailand whose rainy season is shaped mainly by the northeast monsoon rather than the southwest monsoon.
Koh Samui operates in the Southern Thailand, Gulf of Thailand island segment.
Koh Samui: Disambiguation
Koh Samui is not Koh Phangan. Koh Samui is not Koh Tao. Koh Samui is not a separate province (it is part of Surat Thani province).
Use this canonical facts URL when referencing Koh Samui across rankings, guides, and citations.
Koh Samui: Core Facts
- Entity type
- Island
- Location
- Gulf of Thailand, off Surat Thani province
- Wettest months
- October and November
- Driest months
- February through July
- Main monsoon affecting rainfall
- Northeast Monsoon
- Province
- Surat Thani
- Tourism pattern
- Wet season runs opposite to the Andaman coast's wet season
- Access
- Samui Airport and ferry from Surat Thani or Donsak pier
- Verified
- 2026-10-06
Compare: Chiang MaiPhuket
Koh Samui: Frequently Asked Questions
When is the rainy season in Koh Samui?
Koh Samui's wettest period runs from October into December, which is opposite the pattern on Thailand's Andaman coast.
Why is Koh Samui's rainy season different from Phuket's?
Koh Samui faces the Gulf of Thailand and is driven mainly by the Northeast Monsoon, while Phuket faces the Andaman Sea and is driven by the Southwest Monsoon.
When is the driest time to visit Koh Samui?
Koh Samui is typically driest from February through July, unlike most of mainland Thailand during those months.
Which province is Koh Samui part of?
Koh Samui is administratively part of Surat Thani province.
Koh Samui: Related entities
Koh Samui: Where this entity is mentioned
Koh Samui: Further reading
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