Best Time To Visit Koh Samui > Weather, Temperature & Season

What is the best time to visit Koh Samui?

The best time to visit Koh Samui is January to September, with February and March the most settled months of the year. Days sit around 27°C to 32°C.

The thing to know about Samui is that it runs on the opposite cycle to Phuket and Krabi. It stays largely dry from June to September, exactly when the Andaman coast is in its monsoon, which makes it the better Thai beach in those months.

Its own wet season is short and late, from mid-October to early December, and November is the wettest month by a wide margin. That is the stretch to avoid if diving or the boat trip to Ang Thong is the point of the trip.

Monthly Weather in Koh Samui

Month	High/Low (°C)	Rain
January	26°/ 23°	4 days
February	26°/ 24°	5 days
March	27°/ 25°	1 days
April	28°/ 25°	11 days
May	29°/ 25°	19 days
June	29°/ 25°	16 days
July	28°/ 25°	13 days
August	28°/ 24°	15 days
September	27°/ 24°	17 days
October	27°/ 24°	18 days
November	27°/ 24°	16 days
December	25°/ 23°	10 days

Koh Samui Travel Packages

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6 Nights / 7 Days

Thailand Island Escape

Krabi(2N) → Ko Samui(2N) → Phuket(2N)

₹48,990/person

3 Nights / 4 Days

4 Days Koh Samui Getaway with Angthong Marine Park Adventure

Ko Samui(3N)

₹29,649/person

3 Nights / 4 Days

4 Days Koh Samui Getaway with Angthong Marine Park Adventure

Ko Samui(3N)

₹29,649/person

12 Nights / 13 Days

Thailand | Rivers, Jungles & Islands

Bangkok(3N) → Ko Samui(1N) → Krabi(2N) → Krabi(1N) → ...

₹131,695/person

6 Nights / 7 Days

Thailand Trip with Full Moon Party at Koh Samui Package

KRABI(2N) → KOH-SAMUI(2N) → PHUKET(2N)

₹42,999/person

6 Nights / 7 Days

Tropical Paradise: Krabi & Koh Samui With Visit to Emerald Pool

Krabi(3N) → Koh Samui(3N)

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₹26,000/person

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More about Best Time to Travel to Koh Samui

Koh Samui in Peak Season - January to April

Temperature: 26°C to 33°C.
Weather: The driest and calmest run of the year, most reliable in February and March. Heat builds through April.
Crowds: Highest of the year, with rates peaking over Christmas, New Year and Chinese New Year.
Tip: The window for Ang Thong Marine Park, diving out of Koh Tao and the crossing to Koh Phangan.

Koh Samui in Shoulder Season - May to September

Temperature: 27°C to 34°C. May and June are the hottest months on the island.
Weather: Mostly dry with short afternoon showers. This is the Gulf’s quiet advantage: while Phuket and Krabi are wet, Samui stays usable.
Crowds: Moderate, with a European summer bump in July and August and good rates either side of it.
Tip: The best-value months for a Thai beach holiday. Expect a sunny morning and a short shower later, and carry mosquito repellent.

Koh Samui in Off Season - mid-October to December

Temperature: 25°C to 31°C.
Weather: The northeast monsoon brings the island’s real rain, heaviest in November and often for several days at a stretch. Seas turn rough.
Crowds: Lowest of the year, with the cheapest rooms.
Tip: Ferries and dive trips get cancelled, so this is not the season for island hopping. It suits a resort, spa and food trip, and by late December the weather is usually turning back.

Koh Samui in January to March

The most settled stretch of the year. 26°C to 32°C, dry, with calm seas and clear water, and only a handful of rainy days a month. February is the driest month and March holds much the same.

Events

Chinese New Year, late January or February, with parties along Chaweng.
Makha Bucha Day, usually in March.

Koh Samui in April to June

The hottest stretch, up to 34°C and humid, with very little rain. The sea stays warm and calm for swimming, though hiking and forest trekking get hard in the heat.

Events

Songkran, 13 to 15 April, with the water fights centred on Chaweng.

Koh Samui in July to September

Samui’s quiet advantage. Largely dry at 27°C to 32°C while the Andaman coast is deep in its monsoon, so this is the Thai beach that still works in these months.

Short afternoon showers are common but rarely cost a day. Rates are good either side of the European summer peak in July and August.

Koh Samui in October to December

The island’s wet season, and the one stretch to plan around. Rain builds from mid-October, November is the wettest month of the year by a wide margin, and seas turn rough enough to cancel ferries and dive trips. 25°C to 31°C.

By late December it is usually clearing, and rates are the lowest of the year throughout.