What is the weather like in Thailand?

The 3 seasons in Thailand

The rainy season in Thailand

Most of Thailand has a rainy season (monsoon) from May to the end of October. Only the Gulf of Thailand gets its rains a little later: in Koh Samui and the neighboring islands, the peak of the monsoon is in November and December, while July and August are the months with the best weather there. So if you are looking for good weather in July-August, choose Koh Samui, Koh Tao and Koh Phangan rather than the islands of the Andaman Sea (Phuket).

But you can definitely visit Thailand and enjoy your stay during the rainy season. For me, it's even the best season to visit northern Thailand, when nature and landscapes are at their most beautiful! If you travel during the monsoon, you just need to adapt your program and expect heavy rain from time to time, which – except during exceptional weather events – won't really disrupt your trip, especially if you choose the North, the Northeast, Central Thailand and the islands of the Gulf of Thailand.

The hot season in Thailand

The hot season, which we could call summer, runs from March to May. March and April can be scorching, especially in the North and Center of the country, with temperatures regularly exceeding 40°C. At this time of year, a swimming pool or the sea nearby is very welcome!

Winter in Thailand

Obviously, when I talk about winter, it can't be compared with winter in Europe or North America. It is the coolest season in Thailand, but temperatures are far from freezing. In the North, you can experience what the authorities call cold waves, with the thermometer dropping to 12-16°C in the plains. In the mountains, temperatures can approach zero, and sometimes even drop below freezing at the summit of Doi Inthanon, the highest mountain in the country. This cool season lasts from November to March. Note that in November and December, the Gulf of Thailand (Koh Samui, Koh Phangan and Koh Tao) is still very rainy.

Burning season in Thailand

I would add another season – not strictly speaking a season, but important to know about: the PM2.5 or burning season. During this period, a large part of the country suffers from very high levels of fine-particle pollution, especially the North (Chiang Mai, Chiang Rai, Mae Hong Son), but not only. It usually lasts from February to mid-April, with air quality very often at levels considered dangerous for health (wearing an N95 mask is then recommended). It makes your stay less pleasant, and views and landscapes are much less beautiful because the smog reduces visibility. Smartphone apps such as AirVisual and some websites show the air quality index (AQI). Personally, at that time of year, I check these apps more than the weather forecast.

calendar_month The weather in Thailand month by month

The weather in Thailand in January

January is in the middle of what we call winter. The rainy season is over everywhere in the country, although the Gulf of Thailand can sometimes still be quite rainy until mid-January. You can enjoy blue skies and warm weather without scorching heat, so weather-wise, it is a very good time to visit Thailand.

The weather in Thailand in February

February is also in the winter season. The last of the monsoon has left the Gulf of Thailand and it's sunny everywhere, with very little rain. It is precisely this lack of rain – which would otherwise clear the air of the fine particles from the many agricultural fires – that explains the high PM2.5 pollution levels.

The weather in Thailand in March

March marks the start of summer in Thailand, the hottest time of the year, and is the hottest month in the Center and North of the country, with temperatures regularly exceeding 40°C in the middle of the day (10 a.m. to 4 p.m.). In the South, the heat is more bearable, especially by the sea. Hotel swimming pools are particularly welcome!

The weather in Thailand in April

April is also a very hot month, similar to March, especially in the first half. Around mid-April, at the time of Songkran – the Thai New Year, also nicknamed the Water Festival – the weather is supposed to change and the rainy season to begin timidly. This is when nature is at its driest, especially in the North and Center. Not the best time to enjoy lush nature, and some waterfalls have little or no water.

The weather in Thailand in May

The rainy season really starts in May, although it is not the rainiest month of the year. Showers are generally occasional but can be very heavy, and the good weather usually comes back quite quickly – until the next big downpour.

The weather in Thailand in June

In June, the rainy season intensifies. It is still moderate, especially at the beginning of the month, but showers are almost daily – usually short and intense, often in the middle or late afternoon, followed most of the time by pleasant, cloudy weather. The northern and central plains are less rainy than southern Thailand. June is not a bad month to visit the countryside and enjoy nature, even though the seasonal closure of some national parks, which starts in mid-May with the Similan and Surin islands, continues.

The weather in Thailand in July

In July, the monsoon becomes more intense: rain is more frequent and can sometimes last longer. But it is far from raining all the time! You can still enjoy many spells of blue sky. This is the start of the best period to visit northern Thailand: rice is usually planted at the beginning of July, especially in the rice terraces of Ban Pa Pong Piang in Chiang Mai province. The Gulf of Thailand still enjoys good weather, as the monsoon arrives there later (November and December are the rainiest months in that area). In southern Thailand, on the other hand, showers and rainy days become more frequent. You can still visit the South, but you need to be flexible and ready for torrential rain and sometimes a few days of almost continuous rain. Be careful: the sea can be dangerous, so respect the warning flags on the beaches. Every year, several tourists drown in Phuket in July and August.

The weather in Thailand in August

In August, the monsoon intensifies again, especially towards the end of the month. If you plan to visit the South, be ready to adapt and perhaps face a few days of mostly rainy weather, especially on the Andaman Sea coast (Phuket, Krabi, Trang). The islands in the Gulf of Thailand still enjoy good weather and remain the best choice. The North has longer and heavier rainy spells, but also calmer periods that let you enjoy nature, which thrives in this mix of rain and sun.

The weather in Thailand in September

September is clearly the month with the worst weather in Thailand. The monsoon is at its most intense, sometimes with several consecutive days of rain and little respite, and it is usually the month with the most flooding. The South is the wettest, while elsewhere the weather is more unpredictable. I don't recommend planning your holiday in Thailand in September unless you have no choice – and if you do, avoid booking everything in advance and leave room to improvise depending on the weather.

The weather in Thailand in October

October is the last month of the rainy season in most of Thailand (except in the Gulf of Thailand, where the peak of the rainy season is in November and December). It is generally a little less rainy than September, but it remains a very wet month almost everywhere in the country.

The weather in Thailand in November

In November, the rainy season comes to an end in almost the whole country (except in the Gulf of Thailand, where the monsoon peaks until the end of December). The rest of the country enters the cool season: temperatures drop a little but remain warm – this is Thailand, after all! It is rice harvest time in the North and Northeast. The high tourist season starts in mid-November, with lush nature after months of rain, waterfalls at their fullest and beautiful weather. It is one of the best months to visit Thailand (except Koh Samui, Koh Phangan and Koh Tao).

The weather in Thailand in December

In December, rain becomes very rare (except in the Gulf of Thailand, where the monsoon is still at its peak). Temperatures drop a little further, especially in the North, where the thermometer sometimes approaches zero, particularly at the summit of Doi Inthanon, the highest peak in the country. In the plains, however, temperatures generally stay between 20 and 32°C.