When to go
Bangkok has a tropical climate which generally makes it hot and humid throughout the year. Given this, there is not really a best time to go to Bangkok for the weather as it is pretty much a year-round destination.
The cooler season, with averages in the low -mid 20 degrees Celsius, occur between December and February. The hot/dry season is from March to May so if you like it hot this is the best time visit Bangkok. It is also the time when Bangkok celebrates the Thai New Year with great festivity and cheer. Tourists tend to fill the streets of Bangkok during this period, so expect to pay a little more for accommodation and tours.
May to October is regarded as Bangkok’s ‘low’ or rainy season. This is a usually a good time to visit the city as you can get your hands on some great deals on hotels and excursions. It is very rare for the rain to deter tourists who still get to enjoy low-mid 30 degrees Celsius heat during this season.