Your own checklist

Is November a good time to visit Koh Samui?

The quick take

November is usually the wettest month in Koh Samui, so it is a good time to visit only if your plans can stay flexible.

Plan around the rain

Official wet season: October to December²
Ang Thong is calmer March to October⁷
Cover shoulders and knees at temples³

Checklist · 9 points

What to pack for Koh Samui

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ClothesLight clothes and a hat for hot afternoons.¹Closed shoes for the jeep and jungle trails.A rain cape or light jacket in the wet months.

TemplesShirt with sleeves and knee-covering shorts or trousers.³Women: a long skirt and a sleeved top.¹³Slip-on shoes you can remove at the door.⁴

Health and seaInsect repellent, especially October to December.¹⁰^,¹²Follow red flags and lifeguards.¹⁴Book free-cancellation options when rain is likely.

Is November a good time to visit Koh Samui, or should you wait? Here are the station figures for every month, what to wear on a jeep safari and at the temples, and a short packing list.

Editorial team, kohsamuijeepsafari.quest · Updated November 12, 2026 · Quick read: 7 min

In brief

NovemberUsually the wettest month: 452 mm of rain on 15 wet days.¹
Driest stretchFebruary, March and April bring the least rain.¹^,¹^,¹
HeatAfternoons reach 32.9 °C in May, the hottest month.¹
Official wet seasonOctober to December, as the Australian government puts it.²
TemplesShoulders and knees covered, shoes off.³^,⁴

Is November a good time to visit Koh Samui?

Sun for every hour is not what November offers. At the island's own station, 6.4 km from our reference point, the month delivers 452 mm of rain, falling on 15 wet days, the wettest reading of the year.¹ Australia's travel advice points the same way, putting the wet season for Koh Samui and the south-east of the peninsula between October and December.²

That does not make November a write-off. The same station shows afternoon highs of 29.8 °C in the month, so the air stays warm even when the sky is grey.¹ Expect heavy showers to mix with dry hours, and a quieter island for travellers who are ready to adjust plans. Keep your safari and boat days flexible, and book options with free cancellation.

British advice draws the wet season later, from November to March for Koh Samui and south-east Thailand, and warns that the pattern has become harder to predict.⁵^,⁶ Because the official sources differ, the month-by-month station data is the best guide here, and you should plan for some rain whatever the month.

Climate month by month at the Ko Samui station

The chart on this page draws the station's monthly highs, lows and rain. The temperature barely moves through the year. January afternoons average 29.1 °C and nights 24.0 °C, while May reaches 32.9 °C by day.¹^,¹ The year's lowest rain total is in April, with 46 mm.¹ That narrow range is why Samui feels warm in every month and why clothing advice stays simple.

Rain is the real variable, and it changes a lot more than the heat does. February records 51 mm, March 64 mm and April 46 mm, which makes the early months the driest stretch of the year.¹^,¹^,¹ From May the totals climb: 121 mm in May and 153 mm in June, with 9 wet days in June.¹^,¹ The middle of the year is steadier than the end, with July at 111 mm and August at 152 mm.¹^,¹

Then the year tips towards its wettest stretch. September records 129 mm, October 310 mm, November 452 mm and December 270 mm.¹^,¹^,¹^,¹ October and November each average 15 wet days.¹^,¹ If you read only a single line of the table, read this: the island's heavy rain belongs to the last months of the year, not to the middle, so a trip in June or July faces far less rain than a trip in November.

Month by month

Samui temperatures and rain through the year

Jan12.4 h
Feb12.2 h
Mar11.9 h
Apr11.7 h
May11.4 h
Jun11.3 h
Jul11.4 h
Aug11.6 h
Sep11.8 h
Oct12.1 h
Nov12.3 h
Dec12.4 h

Sunless hours around mid-month and the count of days with 2.5 mm or more of precipitation. NOAA, station Ko Samui (temperatures and rainfall for all 12 months), 1991 to 2020.¹

Why Samui's wet months are not the usual Thai ones

Country-wide advice dates Thailand's wet season earlier than Samui's. Canada describes a rainy or monsoon season running from June to November, and Australia gives May to November for the north and centre.⁸^,⁹ For Koh Samui and the south-east of the peninsula, Australia narrows the window to October to December.²

The practical meaning is simple. If you read a general Thailand guide that says the rains end in October, do not assume it applies to Samui. On this island the heaviest rain arrives later than in much of the country, and the middle months of the year can be easier than a national guide suggests. Check the station figures above instead of a countrywide season.

Health advice follows the same local calendar: for Koh Samui and the south-east, Australia flags October to December as the period when insect-borne illness breaks out most often.¹⁰ Canada adds that dengue-carrying mosquitoes bite mostly in daylight, around sunrise and sunset.¹¹ Pack repellent for the wet months.¹²

Your kind of trip

When should you go to Samui?

Choose your priority and see which months suit it.

If I want the driest beach days
February to April
The station shows 46 to 64 mm of rain a month.¹^,¹^,¹
If I want a calm sea for Ang Thong
March to October
TAT says seas are calmer in that window.⁷
If I only care about the jeep safari
Any month
The jeep day can be cancelled free a day ahead.
If I hate heat
Avoid April and May
Afternoons reach 31.8 °C and 32.9 °C.¹^,¹
If I want fewer crowds and can be flexible
October to December
The wet months bring 270 to 452 mm of rain.¹^,¹

Which part of the year

Seasons to compare

Beach first

Dry months

February to April

Rain46 to 64 mm a month
Heat29.4 to 31.8 °C by day
Best forBeaches and boats

Plan this season

Balanced

Showery middle

May to September

Rain111 to 153 mm a month
HeatUp to 32.9 °C by day
Best forInland days

Plan this season

Flexible plans

Wet months

October to December

Rain270 to 452 mm a month
Wet days11 to 15 a month
Best forQuiet travel

Plan this season

Peak season, prices and when to book

Nobody official publishes dates for the Koh Samui peak season in the sources we use, and we will not guess. What the station data does show is that the driest months run from February to April, the stretch with the least rain for beach days. Hotel rates rise and fall with demand, so check your own dates on the booking site before you commit.

For activities the useful feature is flexibility. Both the jeep safari sold here and the half-day temple tour can be dropped without a fee until the day before. That helps in a changeable month: reserve early for the date you want, then move it if a storm is forecast. Boat days work the same way, and TAT notes that ferries may change their timetables with the weather, so reconfirm before you travel.¹⁵

The sea keeps its own calendar. Water around the marine park is calmer from March through October, TAT says, so that is the stretch to choose for the 28 km crossing to Ang Thong.⁷ That window overlaps the drier months in the station data and stretches into mid-year. If a boat day matters to you, aim for it, and leave the inland safari for any month, since a jeep in the rain is part of the fun.

Price your days

Activities for a changeable-weather trip

Type in how many are travelling to compare the wet-weather days.

Choose from 4 options

Activities for a changeable-weather trip

Type in how many are travelling to compare the wet-weather days.

2 people

Jungle safariJeep and lunch · per visitor from $51
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View
Temples half dayMinivan highlights · per visitor from $28
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Tree bridge ziplineJungle zipline · per visitor from $54
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View
Quad bike safariOff-road tracks · per visitor from $54
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View

Starting prices as on the booking platform, converted at the ECB reference rate. You see the exact price at booking.

Through the year

How the Samui year feels

Early months
Dry and warm
February, March and April bring 51, 64 and 46 mm of rain.¹^,¹^,¹
May and June
Hotter, showers return
Afternoons reach 32.9 °C and 32.7 °C.¹^,¹
July and August
Showery middle
Rain totals of 111 mm and 152 mm.¹^,¹
September
Wetter again
129 mm of rain on 9 wet days.¹
October
The wet season builds
310 mm of rain on 15 wet days.¹
November
The wettest month
452 mm on 15 wet days.¹

Safari days in the rain, and in the heat

Can you do a jeep safari in the rain? Often, but expect mud. The half-day highlights operator asks guests to carry a rain cape on wet days and adds that stop order depends on the day's weather and traffic. Canada advises against jungle treks in the rainy season because mudslides are possible, and against mountain roads after dark.¹⁶^,¹⁷ A guided jeep is a sensible answer, because the driver knows when a track is unsafe.

The waterfall swim needs extra care after heavy rain. Rivers and waterfall pools are riskier in the rainy season, the British government cautions, with currents that can be extremely strong.¹⁸^,¹⁹ Follow your guide at Na Muang, stay in the pool areas shown to you and skip the swim if the water looks brown and fast. Missing a swim costs far less than a bad fall.

Heat is the other extreme, and it arrives before the rain does. In May the station averages 32.9 °C in the afternoon and in April 31.8 °C, so a day in an open jeep is hot in the dry months.¹^,¹ Start early, carry water and a hat, and use sunscreen on arms and neck. The jeep safari supplies cool bottled water free of charge on the day, though other drinks cost extra.

Video

When should you visit Koh Samui?

Mike Abroad on YouTube · The video stays unloaded until you press play.

In Koh Samui and the south-east of the peninsula, the wet season is usually from October to December

Smartraveller (Australian Government)²

What to wear in Koh Samui, on the safari and at the temples

What to wear in Koh Samui comes down to the track and the temple. For the jeep or the quad bike, choose clothes you can get muddy, plus closed shoes. The elephant-and-jungle operator asks for comfortable clothes and closed shoes that suit walking and light jungle trails. Bring swimwear for the waterfall and a quick-dry towel.

At temples, cover up despite the heat. TAT wants sleeves and covered knees for men, and for women a sleeved top with a skirt that falls below the knee, with no thin straps.³^,¹³ Visitors enter barefoot, so slip-on shoes help.⁴ Keep a light scarf in your bag to cover shoulders at the Big Buddha or at the mummified monk.

Pack a small rain layer in the wet months and sunscreen in all of them. Cotton and linen suit the climate, and a spare shirt for the ride down the mountain is welcome. If you plan a motorcycle ride, remember that helmets are mandatory for riders and passengers, although many helmets do not meet international safety standards.²⁰ Better still, skip the scooter and go by jeep.

Is June or September a good time to visit Koh Samui?

People also ask about the middle months of the year, so here are the numbers. June at the station averages 153 mm of rain on 9 wet days, with afternoon highs of 32.7 °C.¹ September averages 129 mm on 9 wet days and 31.9 °C by day.¹ Those are showery months, not drenching ones, and the totals are far below October and November.¹^,¹

The sea is the main caution. From May to October, in the rainy season, jellyfish can come close to shore, and the British government warns that stings can be fatal.²¹ It also records drownings in strong riptides and asks swimmers to heed red flags.²² Ask your hotel for local advice before a mid-year swim.

The overall picture is clear enough to plan. For beach-first travellers who hate rain, February to April is the safest window in the data. For an inland-first traveller who wants a jeep safari, almost any month works, and the middle of the year often brings a good balance of dry hours and quiet roads. Treat November as the month to travel with flexibility, or to skip.