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Weather in Koh Samet: the climate month by month

When to go to Koh Samet, how hot it gets and when the rain comes: every month in detail, from the official climate averages of the Thai Meteorological Department, with my own advice on top.

Kylian DevBy Kylian Dev

  • Official 1991–2020 averages
  • 12 months in detail
  • Best time: November to April

In short

The best time to visit Koh Samet is November to April, the driest period of the year. The rainy season runs from September and October, and the wettest month is October, with 224 mm of rain over about 14 days. Daytime highs range from 30.2°C in December to 33°C in April, and nights never drop below about 23.3°C on average.

At a glance

Rain and temperatures in Koh Samet, month by month

Bars show average rainfall; figures above them are the average daytime high and night-time low.

Dry (under 100 mm)Some rain (100 to 200 mm)Rainy (over 200 mm)°/° °C · mm

Month by month

Climate table for Koh Samet

Click a month to see what else happens in Thailand that month: festivals, crowds and the best regions.

MonthHighLowRainRainy daysHumidityVerdict
January30.6 °C23.5 °C16 mm274 %Dry
February31.2 °C24.5 °C20 mm276 %Dry
March32 °C25.5 °C47 mm378 %Dry
April33 °C26.4 °C68 mm577 %Dry
May32.7 °C26.6 °C121 mm978 %Some rain
June32 °C26.4 °C132 mm1077 %Some rain
July31.6 °C26.2 °C104 mm1078 %Some rain
August31.4 °C26.1 °C91 mm978 %Dry
September31.1 °C25.4 °C214 mm1381 %Rainy
October30.9 °C24.7 °C224 mm1483 %Rainy
November30.8 °C24.3 °C57 mm475 %Dry
December30.2 °C23.3 °C12 mm270 %Dry

Total rainfall over the year: 1,106 mm.

Month by month

Koh Samet in each month of the year

Koh Samet in January

Dry

Average highs of 30.6°C and lows of 23.5°C, with 16 mm of rain over about 2 days. A dry month: one of the best times to go.

Koh Samet in February

Dry

Average highs of 31.2°C and lows of 24.5°C, with 20 mm of rain over about 2 days. A dry month: one of the best times to go.

Koh Samet in March

Dry

Average highs of 32°C and lows of 25.5°C, with 47 mm of rain over about 3 days. A dry month: one of the best times to go.

Koh Samet in April

Dry

Average highs of 33°C and lows of 26.4°C, with 68 mm of rain over about 5 days. A dry month: one of the best times to go.

Koh Samet in May

Some rain

Average highs of 32.7°C and lows of 26.6°C, with 121 mm of rain over about 9 days. Some showers, usually short: still a good month to go.

Koh Samet in June

Some rain

Average highs of 32°C and lows of 26.4°C, with 132 mm of rain over about 10 days. Some showers, usually short: still a good month to go.

Koh Samet in July

Some rain

Average highs of 31.6°C and lows of 26.2°C, with 104 mm of rain over about 10 days. Some showers, usually short: still a good month to go.

Koh Samet in August

Dry

Average highs of 31.4°C and lows of 26.1°C, with 91 mm of rain over about 9 days. A dry month: one of the best times to go.

Koh Samet in September

Rainy

Average highs of 31.1°C and lows of 25.4°C, with 214 mm of rain over about 13 days. A rainy month: expect a shower most days and keep plans flexible.

Koh Samet in October

Rainy

Average highs of 30.9°C and lows of 24.7°C, with 224 mm of rain over about 14 days. A rainy month: expect a shower most days and keep plans flexible.

Koh Samet in November

Dry

Average highs of 30.8°C and lows of 24.3°C, with 57 mm of rain over about 4 days. A dry month: one of the best times to go.

Koh Samet in December

Dry

Average highs of 30.2°C and lows of 23.3°C, with 12 mm of rain over about 2 days. A dry month: one of the best times to go.

Seasons

The three things to know about the weather in Koh Samet

Best time

November to April. Least rain of the year, calmer sea on the coast and lots of sunshine. It is also the high season: book early.

Rainy season

September and October. Rain usually comes as heavy showers, often in the afternoon or at night, rather than all day. Peak in October (224 mm).

Hottest month

April, with average highs of 33°C and high humidity. Plan outdoor visits early in the morning.

My advice

What the numbers don't say about Koh Samet

Koh Samet sits in one of the driest corners of Thailand, and there is no official station on the island: these are the figures of Pattaya, about 60 km away. Most of the year you get sun with short showers; only September and October bring regular rain. It is an easy weekend escape from Bangkok almost all year.

Koh Samet
Koh Samet

Where these figures come from

Monthly averages over 1991–2020 from the Pattaya weather station of the Thai Meteorological Department, as published in the World Meteorological Organization climate normals. They describe a typical year, not a forecast: a given year can be wetter or drier.

There is no official weather station in Koh Samet itself, so these are the figures of the nearest station, Pattaya. Local conditions can differ slightly.

Data table (Wikipedia, WMO/TMD normals)
Everything about Koh SametThings to do, food, getting there and budget.Thailand month by monthCompare every region for the month you travel.Travelling in the rainy seasonWhere it rains less and how to plan around it.

FAQ

Weather in Koh Samet: your questions

When is the best time to visit Koh Samet?

November to April is the best time: it is the driest period of the year in Koh Samet, with the most sunshine. It is also the busiest and most expensive season, so book early.

Where to stay in Koh Samet
When is the rainy season in Koh Samet?

The rainy season runs from September and October. The wettest month is October, with about 224 mm of rain over 14 days on average. Showers are heavy but often short: add a light rain jacket to your Thailand packing list.

What is the hottest month in Koh Samet?

April is the hottest month, with average highs of 33°C. The most pleasant month for temperatures is December, with highs of 30.2°C.

Is it worth going to Koh Samet in the rainy season?

Yes, if you stay flexible. Prices drop, there are fewer tourists and the scenery is green. Expect a shower most days, allow spare days for boat trips and get travel insurance that covers cancellations.

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