Koh Samui weather for today, tomorrow and the next 14 days, compared across three independent forecast sources so you can see where they agree before you plan your day. Right now it is 30°C and cloudy in Koh Samui. Tomorrow's forecast: highs of 30°C, lows of 26°C with a 100% chance of rain.
Sources: Open-Meteo, OpenWeather, WeatherAPI · Updated every 12 hours
Koh SamuiThailand
Updated 12:00 PM
Cloudy
Feels like 33°
Forecast Comparison
See how independent weather sources forecast the same location right now.
Forecast agreement
Sources show notable variationTemperature range
28° – 30°
Rain probability
48% – 98%
Wind speed
7 km/h – 16 km/h
Temperature by provider
Hourly forecast
16-day forecast
Rain forecast
Precipitation probability: 100%Hourly precipitation timeline
Wind
Direction: NW
Current wind
7 km/h
Gusts
10 km/h
Hourly wind
Daily wind
Weather alerts
No active weather alerts.
Weather map
Visiting Koh Samui
Thailand's second-largest island, in the Gulf of Thailand, with palm-fringed beaches, resorts and a lively strip at Chaweng. It is a hub for trips to Ang Thong Marine Park, Koh Phangan and Koh Tao.
Best time to visit: January to August. Koh Samui follows a different pattern from Phuket and the Andaman coast: its main rainy season runs from October to December, while the summer months are usually drier than on the west coast.
Landmarks & highlights
- Chaweng Beach
The island's longest and busiest beach, with restaurants and nightlife.
- Big Buddha (Wat Phra Yai)
A 12-metre golden Buddha on a small island joined to the north-east coast.
- Ang Thong National Marine Park
An archipelago of limestone islands, reached on day trips by boat.
- Fisherman's Village, Bophut
An old Chinese-Thai quarter with a walking-street market on Friday evenings.
Local tip: If your dates fall in the Andaman rainy season (May–October), Koh Samui is often the better choice for beach weather in Thailand.
Getting around: Songthaews (shared pick-up taxis) and taxis run around the ring road; many visitors rent a car or scooter.
Good to know: Boats to Ang Thong and the neighbouring islands can be cancelled in rough seas during the November monsoon.
Read the full Koh Samui best-time-to-visit guide →
Koh Samui this time of year
- Humidity near 80% makes 29°C feel stickier than it sounds.
- Nights stay warm, rarely below 27°C — air-conditioning helps.
- There's little difference between day and night (around 1°C).
Planning a trip to Koh Samui? Save or share this forecast.
Koh Samui weather overview: climate, seasons and what to expect
Koh Samui, in Surat Thani, Thailand, sits at approximately 9.51°N, 100.01°E and is home to about 70,000 people. This page compares forecasts from three independent weather providers — Open-Meteo, OpenWeather and WeatherAPI — so you can see at a glance where they agree and where they differ. The data refreshes every 12 hours via ISR.
Koh Samui has a tropical monsoon climate: hot all year, with a short dry season and a very wet one. The warmest month is May, with highs around 30°C; the coolest is January, when nights average 26°C. November is usually the wettest month (about 353 mm). Close to Koh Samui, you can also check Koh Tao (68 km), Krabi (201 km) and Phuket (254 km).
Frequently asked questions
- What is the weather in Koh Samui today?
- Right now Koh Samui shows cloudy conditions at around 30°C (feels like 33°C), based on OpenWeatherMap. The chance of rain today is about 98%. Compare this with the other sources above for a fuller picture.
- What is the weather in Koh Samui tomorrow?
- Tomorrow in Koh Samui: expect a high of 30°C and a low of 26°C, with a 100% chance of rain. See the hourly breakdown above for more detail.
- Will it rain in Koh Samui today?
- The precipitation probability for Koh Samui is around 98% according to OpenWeatherMap. Check the Rain forecast section for the hour-by-hour breakdown and compare with other sources.
- What is the 14-day forecast for Koh Samui?
- The 14-day forecast above shows daily highs, lows and rain probability for Koh Samui from multiple sources; compare them to see how confident the outlook is.
Nearby cities
Highs 28° – 30°C (warmest in May, coolest in Jan)
Highs 28° – 31°C (warmest in Mar, coolest in Jan)
Highs 28° – 30°C (warmest in Mar, coolest in Sep)
Highs 28° – 33°C (warmest in Apr, coolest in Dec)
Highs 29° – 32°C (warmest in Mar, coolest in Dec)
Highs 28° – 31°C (warmest in May, coolest in Dec)
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