Thailand Weather: When’s the Right Time?
They say Thailand has only three basic seasons. It is thought that the first “season” starts in March and lasts up to May, and it’s very hot and dry during those months. The second season lasts from June to October and is usually full of heavy rains. The third season starts in November and ends in February, and it’s the mildest season in Thailand.
Actually, the info above is correct for the Northern part of Thailand and not for the whole country, since there are only two seasons in the Southern regions – the wet and the dry. There are many heavy rains and storms on the southwest coast from April till October; as for the southeast coast, the rain season there starts in September and lasts till December.

I bet you now wonder when the best time to visit Thailand is. Of course, this depends on you, your preferences and on what exactly you plan to do there. I think that generally, the best time to travel to this wonderful country is from November to February. Why? Well, it’s the coolest season there. In Bangkok the temperature is about 18-32º C, and it’s usually much colder in the Northern regions – 8-12º C usually.
But there is one little “but” here… This is when most tourists prefer to travel to Thailand, so you must be ready to face some… “competition”
All the resorts and Bangkok hotels can be full, prices rise and sometimes it can be difficult to find a place to stay at a reasonable price… If you want to travel anyway at this time of the year, Expedia hotels offer some great deals when you book in advance.

For me, the worst time to spend a holiday in Thailand is the “summertime” that lasts from March to June. In Bangkok it’s usually 34-40º C with humidity levels of 75%… So you can consider going there in summer only if you really love hot weather. But take into account that air quality in Bangkok becomes much worse during these months. Also remember that April is the hottest month in all Thailand, so you can spend it there only if you’re planning to swim in the ocean during the whole day. Oh, and one more thing: You better not go to the Big Mango during these hot months.

As I mentioned above, July-October are the monsoons months, when the average temperature in Bangkok is around 29º C and the humidity grows till 90%. It’s the best time for those who love rains. Perhaps having holidays in Thailand during these months is a good idea for some romantic couples, too.
Thailand weather is always cool during this rain season, and the air is always fresh. Plus there aren’t many tourists in the country, and you can find better and cheaper places to stay. So July-October’s weather in Thailand can also be very good for tourists. Oh, and don’t be afraid of the rains. “Rainy season” doesn’t mean it’s raining day and night.

The heavy rains usually stop in October, when the wind changes its direction. The Northeast winds usually bring dry air, but the weather in the months following October is usually unpredictable. So you can visit Thailand after October, if you love surprises!
Here you can find some interactive information about the weather in Thailand. It can be useful for you if you’re planning a trip in the nearest future.