Best time to visit Koh Yao

The best time to visit Koh Yao is during the dry season from early-December to early-March when the skies are clear and sunny averaging 28°C (82°F).


Koh Yao weather

Koh Yao enjoys a tropical monsoon climate with warm temperatures year round spread across three distinct seasons: warm – November to February; hot – March to May; and wet – May to October.

The average temperature throughout the year remains a consistent 30°C (86°F).

The warm, dry season from November to March sees the best weather of the year with temperatures ranging between 23°C (73°F) and 31°C (87°F).

Which is the hottest month in Koh Yao?
The hottest month of the year in Koh Yao is normally April when maximum daytime temperatures usually reach 33°C (91°F) with very high heat and humidity, and a low of 25°C (77°F).

The hot season from February to April sees daily highs average 33°C (91°F), with the first thunderstorms arriving in April.

Which is the coldest month in Koh Yao?
The 'coldest' month of the year in Koh Yao is December, averaging 27°C (73°F) with an average high of 31°C (87°F) and a low of 23°C (73°F).

Seawater is warm and calm in December.

Which is the sunniest month in Koh Yao?
The sunniest time of year in Koh Yao is usually February with an average of 9 hours of sunshine per day; that's on average 78% of daylight hours.

Which month has the most rain in Koh Yao?
September is usually the wettest month with 323mm of rain on average, while October sees the most wet days – 20 days on average with some rain.

The wet season from late-April to early-December brings hot days and torrential rain that falls mainly in the afternoon and evening.

Temperatures average 29°C (84°F) with highs of 31°C (87°F) from May onwards. You can also expect high humidity and the seawater becomes cloudy and often rough.

When is the sea warmest in Koh Yao?
The sea is usually at its warmest in Koh Yao in April when the water temperature reaches 30°C (86°F).

Which is the windiest month in Koh Yao?
The windiest month of the year in Koh Yao is August, with an average hourly wind speed of 10.5 kilometres per hour (5.6 knots).

The windy part of the year lasts from late-May through to early-October, with average wind speeds of more than 8.6 kilometres per hour (7 knots).

The less-windy time of year lasts from early-October through to late-May. The calmest month of the year in Koh Yao is April, with an average hourly wind speed of 6.7 kilometres per hour (3.6 knots).

The predominant average hourly wind direction varies throughout the year in Koh Yao.

Best time for activities?
Snorkelling, sunbathing and water sports are best between November and April.


Koh Yao – Monthly Weather

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Average daily max temp (°C)
32 33 34 33 32 32 31 31 31 31 31 31
Average daily min temp (°C)
23 23 24 25 25 25 25 25 24 24 24 23
Daily hours of sunshine
9 9 9 8 6 5 6 6 5 6 7 8
Daily hours of daylight
12 12 12 12 13 13 13 12 12 12 12 12
Comfort level
Very high heat & humidity icon Very high heat & humidity icon Extreme heat & humidity icon Very high heat & humidity icon Very high heat & humidity icon Very high heat & humidity icon High heat & humidity icon High heat & humidity icon High heat & humidity icon High heat & humidity icon High heat & humidity icon High heat & humidity icon
Average relative humidity (%)
75 75 75 80 85 85 85 85 85 90 85 80
UV Index (max)
11 11+ 11+ 11+ 11+ 11+ 11+ 11+ 11+ 11+ 11 10
Number of days with some rainfall
4 3 6 11 17 15 16 16 19 20 16 9
Average monthly rainfall (mm)
30 22 61 116 213 216 218 254 323 285 183 81
Average wind speed (km/h)
9 8 7 7 8 10 10 10 9 8 8 9
Average daily sea temp (°C)
28 29 29 30 30 30 30 29 29 29 29 29
Koh Yao Yai, Thailand

Holiday seasons

High Season: November to April

Low Season: May to October brings less crowds, cheaper accommodation and, as the locals are quick to point out, it does not rain all day.


Note: Meteorological data is sourced from the United States National Oceanic and Atmospheric Administration (NOAA) and the World Meteorological Organization (WMO), with additional historical climate data sourced from the Thai Meteorological Department.


More about Koh Yao Yai…



Latest update: Best time to visit Koh Yao: 11 July, 2022



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