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What is the weather in Koh Samui in Thailand?
Koh Samui is a beautiful island located in the Gulf of Thailand, known for its pristine beaches, lush tropical forests, and warm weather. The climate in Koh Samui is tropical, which means it is warm and humid throughout the year. However, the island experiences two distinct seasons – a dry season and a rainy season.
☀️ The dry season in Koh Samui runs from December to February, and this is considered the peak tourist season on the island. During this time, the weather is generally sunny and dry, with very little rain. The temperature ranges from 25 to 30 degrees Celsius, making it a perfect time to enjoy the beaches and other outdoor activities.
From March to August, Koh Samui experiences a transitional season, where the weather can be a bit unpredictable. It can be hot and humid during the day, with the occasional rain shower in the afternoon or evening.
⛈️ The rainy season Koh Samui runs from September to November, and during this time, the island experiences heavy rainfall and thunderstorms. The weather can be unpredictable, with some days experiencing constant rain, while others are sunny and dry. Temperatures during this season usually range between 23 to 28 degrees Celsius.
If you’re planning to visit Koh Samui during the rainy season, it’s important to pack a raincoat or umbrella as the rain can be quite heavy at times. However, the upside of visiting during this time is that the island is less crowded, and you can enjoy the lush greenery that comes with the rain. Aside from the weather, Koh Samui is also known for its beautiful temples, delicious Thai cuisine, and vibrant nightlife. It’s a popular destination for both backpackers and luxury travelers alike, and there’s something for everyone on this tropical island.
What is the best time to visit Koh Samui?
The best time to visit Koh Samui depends on your preferences and what you want to do while you’re on the island. If you’re looking for the driest and sunniest weather, the best time to visit Koh Samui in Thailand is during the dry season, which runs from December to February. During this time, you can expect clear blue skies and warm temperatures, making it perfect for lounging on the beach and other outdoor activities.
If you’re looking to avoid the crowds and save some money, you might want to consider visiting Koh Samui during the shoulder season, which runs from March to August. During this time, the weather can be a bit more unpredictable, but there are still plenty of sunny days to enjoy, and you can often find great deals on accommodation and activities.
If you’re not too bothered by a bit of rain and want to experience Koh Samui’s lush greenery and quieter atmosphere, the rainy season from September to November might be the best time for you. Just keep in mind that some businesses and attractions may close during this time, and there is a higher chance of storms and rough seas.
What is the current weather in Koh Samui? ➜ Current weather in Koh Samui.
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Weather in Koh Samui throughout the year:
| Month | Weather Description |
|---|---|
| January in Koh Samui | January is a great time to visit Koh Samui, as it falls within the dry season on the island. The weather is generally sunny, warm, and dry, with an average temperature range of 24 to 29 degrees Celsius (75 to 84 degrees Fahrenheit). You can expect clear blue skies and very little rain during this month, making it perfect for enjoying Koh Samui’s beautiful beaches and outdoor activities like snorkeling, diving, and hiking. The sea is generally calm and perfect for swimming, and the evenings are usually pleasant and cool. |
| February in Koh Samui | February is another great month to visit Koh Samui, as it still falls within the dry season on the island. The weather is similar to January, with warm temperatures ranging from 24 to 29 degrees Celsius (75 to 84 degrees Fahrenheit), clear blue skies, and very little rainfall. This month is also known for its relatively low humidity levels, making it more comfortable for outdoor activities like hiking and sightseeing. The sea is still calm and perfect for swimming, and the evenings are usually pleasant and cool. |
| March in Koh Samui | In March, Koh Samui begins to transition into the hotter and more humid months of the year. Temperatures can range from 25 to 31 degrees Celsius (77 to 88 degrees Fahrenheit), and there may be occasional short rain showers in the afternoons or evenings. However, the weather is still generally dry and sunny, and the sea remains calm and great for swimming. March is a great month to enjoy outdoor activities like diving, snorkeling, and exploring the island’s beautiful waterfalls and national parks. |
| April in Koh Samui | April is the hottest month of the year in Koh Samui, with temperatures ranging from 26 to 33 degrees Celsius (79 to 91 degrees Fahrenheit). The humidity is also higher, making it feel even hotter. Despite the heat, April is still a popular time to visit Koh Samui, as it is during the Thai New Year (Songkran) celebrations. The island comes alive with water fights, street parties, and cultural festivities. |
| May in Koh Samui | May marks the beginning of the rainy season on Koh Samui, with temperatures ranging from 25 to 31 degrees Celsius (77 to 88 degrees Fahrenheit). The rainfall starts to become more frequent, with short but heavy showers occurring throughout the day. Despite the rain, Koh Samui still sees a steady stream of visitors during this month, as the island is less crowded and more affordable than during the peak tourist season. It’s a good time to take advantage of the lower prices and enjoy some indoor activities like spa treatments, shopping, and exploring the island’s temples and museums. |
| June in Koh Samui | June is still considered part of the rainy season on Koh Samui, with temperatures ranging from 25 to 30 degrees Celsius (77 to 86 degrees Fahrenheit). The rainfall is more frequent and longer-lasting, with occasional thunderstorms. Despite the rain, there are still plenty of things to do on the island, such as indoor activities like visiting museums, art galleries, and shopping centers. The upside is that the island is less crowded, and the hotels offer better deals. |
| July in Koh Samui | July sees similar weather to June, with frequent rainfall and high humidity. Temperatures range from 25 to 30 degrees Celsius (77 to 86 degrees Fahrenheit), making it hot and sticky on the island. Despite the weather, July is still a great time to visit Koh Samui for those who want to avoid the crowds and enjoy some indoor activities. It’s also a great month for spa treatments and wellness activities, which are plentiful on the island. |
| August in Koh Samui | August is still considered part of the rainy season on Koh Samui, with temperatures ranging from 25 to 30 degrees Celsius (77 to 86 degrees Fahrenheit). The rainfall is still frequent, but there are often breaks of sunshine throughout the day. August is a great time for water-based activities like snorkeling, diving, and surfing, as the sea is often rougher and more exciting during this time of year. It’s also a great time for indoor activities like visiting museums, galleries, and shopping. |
| September in Koh Samui | September is typically the wettest month of the year on Koh Samui, with temperatures ranging from 24 to 29 degrees Celsius (75 to 84 degrees Fahrenheit). The rainfall is heavy and can last for long periods, so outdoor activities may be limited. Despite the weather, September is still a great time to visit Koh Samui for those who want to avoid the crowds and enjoy some indoor activities. It’s also a great time to take advantage of the lower prices offered by the hotels and resorts on the island. |
| October in Koh Samui | October marks the end of the rainy season on Koh Samui, with temperatures ranging from 24 to 29 degrees Celsius (75 to 84 degrees Fahrenheit). While there may still be occasional showers, the rainfall becomes less frequent, and the weather starts to clear up. The sea can still be a bit rough, but it’s a good time for water-based activities like surfing and diving. Visitors can also enjoy the beautiful greenery of the island as the vegetation becomes lush after the rainy season. |
| November in Koh Samui | November is a great time to visit Koh Samui, with warm temperatures ranging from 24 to 29 degrees Celsius (75 to 84 degrees Fahrenheit). The weather is generally sunny and dry, and the sea is calm and perfect for swimming. It’s a great time to explore the island’s beautiful beaches, temples, and national parks. November is also a great month for those who want to avoid the crowds and enjoy some peace and quiet. |
| December in Koh Samui | December is the start of the high season on Koh Samui, with temperatures ranging from 24 to 29 degrees Celsius (75 to 84 degrees Fahrenheit). The weather is sunny and dry, and the sea is calm and perfect for swimming. This month is an excellent time for outdoor activities like sunbathing, swimming, and exploring the island’s beautiful scenery. It’s also a great time for Christmas and New Year celebrations, as the island comes alive with festivities and parties. |
The Current weather in Koh Samui – Thailand:
Max, Min and Average Temperature in Koh Samui:
The average temperature in Koh Samui ranges from around 24°C (75°F) to 32°C (90°F) throughout the year. The island experiences a tropical climate, which means it is hot and humid all year round. During the dry season (December to February), the average temperature ranges from 26°C (79°F) to 28°C (82°F), with occasional cool breezes. The maximum temperature during this season can reach up to 34°C (93°F), while the minimum temperature can drop to around 22°C (72°F) at night. During the hot season (March to May), the average temperature can reach up to 33°C (91°F), with the maximum temperature reaching up to 36°C (97°F) in April. The minimum temperature during this season can be around 25°C (77°F) at night.
| Month | Aver. Temp. (°C) | Aver. Max. Temp. (°C) | Aver. Min. Temp. (°C) |
|---|---|---|---|
| January | 26 | 30 | 22 |
| February | 27 | 31 | 23 |
| March | 28 | 33 | 24 |
| April | 29 | 34 | 25 |
| May | 28 | 32 | 25 |
| June | 28 | 31 | 24 |
| July | 28 | 31 | 24 |
| August | 28 | 31 | 24 |
| September | 28 | 31 | 24 |
| October | 27 | 31 | 24 |
| November | 27 | 31 | 23 |
| December | 26 | 30 | 23 |
Rainfall and Rainy Days in Koh Samui:
Koh Samui has a tropical climate and experiences two main seasons: the dry season (December to February) and the rainy season (May to November). During the rainy season, the island experiences a significant amount of rainfall, often in the form of short but heavy showers. On average, Koh Samui receives around 2,000mm (79 inches) of rainfall per year, with the heaviest rainfall occurring in October and November. During these months, the island can experience up to 500mm (20 inches) of rainfall. Despite the rainy season being characterized by frequent showers, there are still plenty of sunny days throughout the season.
| Month | Aver. Monthly Rainfall (mm) | Aver. Rainy Days |
|---|---|---|
| January | 90 | 6 |
| February | 40 | 5 |
| March | 60 | 5 |
| April | 100 | 9 |
| May | 180 | 16 |
| June | 100 | 12 |
| July | 100 | 12 |
| August | 110 | 12 |
| September | 130 | 15 |
| October | 300 | 20 |
| November | 340 | 20 |
| December | 120 | 10 |
Max and Average Wind Speed and Wind Gust in Koh Samui:
Koh Samui experiences moderate to strong winds throughout the year, with the highest wind speeds occurring during the rainy season. The wind patterns are influenced by the prevailing northeast and southwest monsoons. On average, the maximum wind speed in Koh Samui is around 20 km/h (12 mph), with the highest wind speeds occurring in November and December. During these months, the island can experience wind gusts of up to 40 km/h (25 mph) or more. The average wind speed in Koh Samui is around 10 km/h (6 mph) throughout the year. It’s worth noting that the wind conditions can have an impact on water activities such as snorkeling, diving, and water sports. Visitors should check the weather and wind conditions before participating in any water activities.
| Month | Average Wind Speed (km/h) | Max Wind Speed (km/h) | Max Wind Gust (km/h) |
|---|---|---|---|
| January | 9 | 21 | 35 |
| February | 9 | 21 | 35 |
| March | 10 | 22 | 35 |
| April | 9 | 21 | 35 |
| May | 11 | 23 | 35 |
| June | 13 | 26 | 40 |
| July | 13 | 27 | 40 |
| August | 12 | 26 | 40 |
| September | 11 | 24 | 40 |
| October | 10 | 23 | 40 |
| November | 10 | 23 | 40 |
| December | 9 | 21 | 35 |
Cloud and Humidity in Koh Samui:
The island receives a good amount of sunshine throughout the year, with the most sunny days occurring during the dry season. The humidity in Koh Samui can be quite high, especially during the rainy season. The island is generally more humid in the mornings and evenings, with slightly lower humidity levels during the middle of the day. The average humidity in Koh Samui is around 80%, but it can reach up to 90% or more during the rainy season. Cloud cover can also vary throughout the year, with more cloudy days occurring during the rainy season. However, even during the rainy season, there are still many sunny days with blue skies. Visitors should also note that the cloud cover can vary depending on the location on the island.
| Month | Average Cloud Cover (%) | Average Humidity (%) |
|---|---|---|
| January | 40 | 70 |
| February | 40 | 70 |
| March | 40 | 70 |
| April | 40 | 70 |
| May | 50 | 75 |
| June | 60 | 80 |
| July | 60 | 80 |
| August | 60 | 80 |
| September | 60 | 85 |
| October | 60 | 85 |
| November | 50 | 80 |
| December | 40 | 70 |
Sun Hours and Sun Days in Koh Samui:
Koh Samui is known for its tropical climate and sunny weather throughout the year. The island receives plenty of sunshine even during the rainy season, with most days experiencing some sun hours. The number of sun hours per day and sun days per month in Koh Samui can vary depending on the season. The dry season generally has more sun hours and sun days, while the rainy season experiences occasional overcast skies.
| Month | Aver. Sun Hours per Day | Aver. Sunny Days per Month |
|---|---|---|
| January | 8 | 25 |
| February | 9 | 26 |
| March | 9 | 27 |
| April | 8 | 25 |
| May | 7 | 23 |
| June | 6 | 19 |
| July | 6 | 19 |
| August | 6 | 19 |
| September | 6 | 18 |
| October | 7 | 22 |
| November | 8 | 24 |
| December | 8 | 24 |
Visibility in Koh Samui:
Visibility is an important factor to consider when planning a trip to Hua Hin. Good visibility means clear, unobstructed views of the town’s beautiful scenery, while poor visibility can obscure landmarks and make it difficult to enjoy outdoor activities. In Hua Hin, visibility is generally good throughout the year, with the exception of the monsoon season from May to October. During this time, the town experiences occasional haze and fog, resulting in reduced visibility. However, visibility usually returns to normal within a few hours.
| Month | Average Visibility (km) |
|---|---|
| January | 9.7 |
| February | 10.0 |
| March | 10.0 |
| April | 9.9 |
| May | 9.7 |
| June | 9.4 |
| July | 9.3 |
| August | 9.3 |
| September | 9.5 |
| October | 9.7 |
| November | 9.8 |
| December | 9.8 |
What is the sea temperature in Koh Samui:
The sea temperature in Koh Samui varies throughout the year, with the warmest months being from March to August, and the coolest months being from December to February. The sea temperature in Koh Samui averages around 27 to 29 degrees Celsius (81 to 84 degrees Fahrenheit) during the year. The warm sea temperature in Koh Samui makes it an ideal destination for beach activities such as swimming, snorkeling, and scuba diving. The waters are also relatively calm during the dry season, making it an excellent time for water sports activities. During the rainy season, which lasts from September to November, the sea temperature may decrease slightly, but it still remains warm and comfortable for swimming and water activities. However, it is important to be cautious of the weather conditions during the rainy season, as the waters can become rough and dangerous for swimming.
| Month | Aver. Sea Temp. (°C) | Aver. Sea Temp. (°F) |
|---|---|---|
| January | 27 | 81 |
| February | 27 | 81 |
| March | 28 | 82 |
| April | 29 | 84 |
| May | 29 | 84 |
| June | 29 | 84 |
| July | 29 | 84 |
| August | 29 | 84 |
| September | 29 | 84 |
| October | 29 | 84 |
| November | 28 | 82 |
| December | 27 | 81 |
❓ Frequently Asked Questions – Weather in Koh Samui:
1. What is the best time to visit Koh Samui?
-
- The best time to visit Koh Samui is during the dry season from December to April. During these months, the weather is generally sunny and dry, making it perfect for outdoor activities and beach adventures. The sea is also calmer during this time, which is ideal for swimming and water sports.
2. What is the temperature like in Koh Samui?
-
- The temperature in Koh Samui ranges from 25 to 35 degrees Celsius (77 to 95 degrees Fahrenheit) throughout the year. The warmest months are from March to August, while the coolest months are from December to February.
3. What is the rainy season like in Koh Samui?
-
- The rainy season in Koh Samui lasts from September to November, with the heaviest rainfall occurring in October. During this time, the weather can be unpredictable, with occasional thunderstorms and heavy rainfall. It is important to be cautious during the rainy season, as the waters can become rough and dangerous for swimming.
4. What is the humidity like in Koh Samui?
-
- The humidity in Koh Samui is generally high throughout the year, ranging from 70% to 90%. This can make the weather feel hotter and more uncomfortable, particularly during the rainy season.
5. What is the wind like in Koh Samui?
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- The wind in Koh Samui is generally calm throughout the year, with occasional gusts during the rainy season. The average wind speed is around 10 to 15 kilometers per hour (6 to 9 miles per hour).
6. What is the sea temperature like in Koh Samui?
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- The sea temperature in Koh Samui ranges from 27 to 29 degrees Celsius (81 to 84 degrees Fahrenheit) throughout the year. The warmest months are from March to August, while the coolest months are from December to February.
7. What is the visibility like in Koh Samui?
-
- The visibility in Koh Samui is generally good throughout the year, with clear skies and sunny weather during the dry season. However, visibility can be affected by rainfall and storms during the rainy season.
8. How many hours of sunshine can I expect in Koh Samui?
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- Koh Samui receives an average of 7 to 9 hours of sunshine per day throughout the year, with the most sunshine occurring during the dry season from December to April.
9. What is the average rainfall in Koh Samui?
-
- The average rainfall in Koh Samui is around 2,000 millimeters per year, with the heaviest rainfall occurring during the rainy season from September to November.
10. How many rainy days can I expect in Koh Samui?
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- Koh Samui experiences an average of 15 to 20 rainy days per month during the rainy season from September to November.
11. What is the UV index like in Koh Samui?
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- The UV index in Koh Samui is generally high throughout the year, ranging from 7 to 11. It is important to wear sunscreen and protective clothing to avoid sunburn and skin damage.
12. What should I wear in Koh Samui?
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- Lightweight and breathable clothing is recommended for Koh Samui, as the weather can be hot and humid throughout the year. It is also recommended to bring a light jacket or sweater for cooler evenings, particularly during the dry season.
13. Is it safe to swim in Koh Samui?
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- It is generally safe to swim in Koh Samui, particularly during the dry season when the waters are calmer. However, it is important to be cautious during the rainy season, as the waters can become rough and dangerous for swimming.
14. Where you can travel from Koh Samui?
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- From Koh Samui you can also travel by boat / ferry to Koh Phangan or popular and small Koh Tao Island. You an also go by boat to Surat Thani town – the most frequented transport junction in central part of Thailand.
15. How to travel solo in Thailand?
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- Embark on a solo adventure in Thailand by researching destinations, ensuring personal safety, trying local experiences, connecting with fellow travelers, and savoring the diverse landscapes and attractions the country has to offer. Traveling on your own in Thailand is very popular by travelers. Read this article: Solo Travel in Thailand.
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