The rainy season in Thailand varies depending on the region and is influenced by the monsoon. In most of Thailand rainy season is experienced from May to October. The rainy season on the east coast of Southern Thailand (Koh Samui, Koh Phangan) normally starts later and can last until the beginning of December.
August and September, being the most densely abundant rainfall months, favor a high chance to meet tropical cyclones passing through the Upper Thailand. As a result, heavy to very heavy rain amounts occur in many areas. Furthermore, flash and forest flood with overflow may inundate in some areas. However, the east coast of Southern Thailand gets the heaviest rainfall in November.
Even if the rainy season in Thailand might look less attractive for visiting the country, the weather here is still very warm and the rain in most cases come as a short strong shower in the afternoon. It means that you still can get plenty of sunshine and avoid crowds of tourists. Bargain deals for various accommodations are normally offered during this time as well. Just keep your trip plan flexible and you will have a nice holiday during Thailand’s rainy season.
Rainy Season Outlook by Month
During the first half of July, the amount and distribution of rainfall might be reduced. Thus, dry spell may occur and causing to water shortage for agricultural usage in many areas, specifically in repeated drought areas outside irrigation zones. The reason for this is that the Southwest Monsoon prevailing over the Andaman Sea and Thailand weakens whereas the monsoon trough is about to move up to prevail over the southern part of China.
August - September
August until September, densely abundant rainfall occurs. Consequently, flash and forest flood together with overflow feasibly appear in many areas. The reason is that the Southwest Monsoon prevailing over the Andaman Sea and Thailand comes back actively and continuously. The monsoon becomes active periodically while the monsoon trough prevails over the Upper Thailand occasionally.
The northern and northeastern parts of Thailand get less rainfall and start to meet morning chilly weather, especially in the upper parts. Nevertheless, the central, eastern part of the country and the Southern Thailand still meet densely abundant rainfall further together with heavy rain amount in many areas. The reason for this is that high-pressure air mass areas from China begin to prevail over the upper areas of both of the northern and northeastern parts. In addition, the Southwest Monsoon trough moves downward to prevail over the lower portion of the central part, the upper portion of the Southern Thailand and the eastern part. Moreover, the former prevailing Southwest Monsoon over Thailand transforms to become the prevailing Northeast Monsoon instead.
Tropical cyclones (depressions, tropical storms and typhoons)
During the rainy season, 1-2 tropical cyclones are expected to move towards Thailand. It favors a high chance to move pass the northeastern and northern parts in August or September. Furthermore, gusty wind waves appear in coastal areas, where wave height may reach 3 - 4 meters in some periods. Thus, you should be cautious of these natural hazards and follow the news attentively during the tropical cyclone periods.
Where to go during the rainy season?
Thailand, like Vietnam, is a vast country and at the same time in different regions the weather can be quite diverse. There is a lot of information about the rainy season in different parts of Thailand on the Internet, but it is often contradictory. You can find more advices for traveling during Thailand rainy season here, so you can adjust your travel route accordingly.
Bangkok and Central Thailand
One of the first things you feel when you leave Bangkok airport is the high humidity that can rise to 90 percent for a short time, which can be problematic for older travelers. The temperatures in Bangkok are around 28-30 degrees. In Bangkok, the rainy season is most intense in September and October. You can expect around 17-23 rainy days every month with one-hour downpour that usually falls in the afternoon. The rain is not as heavy and not as long as on Koh Samui or Koh Phangan. In June - July you can expect short rains and thunderstorms. September is the wettest month for Bangkok and the surrounding area. The floods can happen on the outskirts of the city, but they do not happen every year.
The months of June to August are dominated by the rainy season in the north of Thailand. With 15-20 rainy days per month and an average of 220 mm of precipitation, excursions can literally fall into the water during this time. However, if you are travelling during this time, you can admire the lush green rice fields and the alive nature. It is a wonderful time to explore the north of Thailand in between the showers.
Northeast Thailand - Isan
The rainy season in the northeast of Thailand lasts from May to October. Nature lovers should travel to Isan during this time as everything glows in rich green.
In Eastern Thailand these months can be very changeable. You can be lucky with a dry period, but should also expect a lot of rain and strong wind. The peak of the rainy season is between September and October. The islands are still accessible by ferry, although Koh Mak and Koh Kood are less accessible due to the rough seas.
Southern Thailand - East Coast (The Gulf of Thailand)
The Southeastern Gulf of Thailand with Koh Samui, Koh Phangan and Koh Tao remains the best choice when it comes to island hopping during the rainy season in Thailand. The east coast has the least rainfall. Don't expect completely sunny days, but the weather here is certainly better than in Phuket and other west coast destinations.
On these islands, the rainy season starts in October and ends in November. Of course, it rains, but usually it happens at night or early in the morning and lasts no more than two hours, after which everything dries up very quickly. In general, you still have the chance to soak in the sun. On the island, it does not get significantly colder than 26 degrees. At this time, you are rewarded with significantly emptier beaches and extremely low accommodation costs.
Southern Thailand – West Coast (The Andaman Sea)
During the rainy season, weather is more violent in the south, as it rains even stronger in the southwest than in the Gulf of Thailand. You should expect rain every day when you travel to Phuket, Koh Phi Phi, Koh Lanta or Krabi. The rainy season here is from June to September, with September usually having the most of rainy days in the region of Southwest Thailand. The weather can be turbulent with rough seas as a result so this is the time for some good surfing! Many tourists decide to travel to these areas during this time because it never stays rainy all day. There are also days and even weeks, when it is mainly sunny and dry. However, there can also be longer periods of rain when only indoor activities are possible.
Rainy Season in Thailand's Cities & Islands
As the weather in Thailand differs quite a lot, depending on the region and the time of the year, our chart of rainy weather ratings will help you to get an idea about the rainy season in Thailand's cities and islands.
★★★★★ - chance of getting wet is close to minimum
★★★★☆ - a bit of rain every few days might be expected
★★★☆☆ - the rain isn't constant and long lasting, if any
★★☆☆☆ - chances of rainy day are bigger than 50/50
★☆☆☆☆ - lots of rain can be expected
The rainy season in these Thailand's cities and islands comes at the same time:
- Bangkok and Ayutthaya, Lopburi
- Chiang Mai and Chiang Rai, Sukhothai, Pai
- Krabi and Koh Phi Phi, Koh Lanta, Koh Lipe
- Phuket and Khao Lak, Phang-nga, Koh Phayam
- Koh Samui and Koh Phangan, Koh Tao
- Pattaya and Koh Samet
- Koh Chang and Koh Kood
- Hua Hin and Cha-am
Is it worth traveling in the rainy season?
Traveling to Thailand during the rainy season is less predictable. The rainy season in Thailand runs roughly from July to October but the monsoon period varies by region. Rain usually gets peaking in September and October, when dirt roads are turned into muddy roads. As already mentioned, this does not mean that it will rain all day long. Often the rain showers are very heavy but last for short with only one to two hours a day or it pours freely all night and the next morning. But with a bit of luck, the rain can only take a few minutes and the sun shines again. The only unpleasant thing about the rainy season is the high humidity, which can then rise up to 90%, so you should be able to deal with that.
If you are prepared for these rainy days, you can spend a great holiday in Thailand even during the rainy season. But you should be mentally prepared for the fact that it can rain longer. The flexible travel planning will help you. You can get an umbrella and go out to sit at the café, join the cooking class and discover what Thai cuisine has to offer, take an extensive massage or SPA, or buy some nice souvenirs for home.
In addition, nature is beautifully green and waterfalls come to life. If you can wait, the months of November and December are highly recommended to visit Thailand because the landscape is still green, the rice fields are in bloom and the abundance of water at waterfalls due to the rainfall in the previous months. The rainforests and national parks are just gorgeous during this time.
Another big advantage of Thailand's rainy season is that prices drop with fewer people coming. Yes, sometimes you have the whole beach to yourself! Buses, trains and planes are less crowded, which means that you can generally travel more comfortably than in the high season. Many accommodations are available at good price. Domestic flights are also cheaper. You can easier negotiate the price on activities. If you want to spend less, book a vacation in Thailand between June and October.
If you want to be sure that you will have clear blue skies and pleasant temperatures, book your holiday in other period, but keep in mind that hotels and flights are likely to cost more. One important note is that even in other months there is no one hundred percent guarantee of good weather. Climate change is now also clearly noticeable in Thailand.
We recommend planning your vacation in advance depending on the place where you want to travel, in this case your trip will be as pleasant as possible and will leave only positive memories.
Tips for the rainy season travel
You should make sure your backpack and daypack are waterproof or buy a handy rain cover.
The rainy season is the same as the mosquito season so stock up on special remedies to avoid catching any disease. Read our tips in the extensive blog about Vaccinations for Thailand Travel to protect yourself well.
It is not recommended to drive a motorcycle or scooter in heavy rain, even if you are wearing a raincoat, as it is not safe at all, strong winds and rain impair visibility on the road, and traffic in Thailand can be unpredictable.
Sometimes, heavy rain amounts occur continuously for many days. As a result, flash floods with overflow may inundate, specifically during August until September. You should follow the daily weather forecast news closely.