It’s been said that there are only three seasons in Thailand: hot season, hotter season, and hottest season. I kid . . . Thailand has three seasons: the hot season, the cold season, and the rainy season. Now, you may debate if 75F is ‘cold’ or not, but that’s how it is in most of Thailand. Of course, each region of Thailand has different extremes for each season, so this article is over-generalizing a bit.
The Cold Season
The cold season is generally from November to February. In Bangkok this means it might get as cold as 60F at the coldest point of the night, but more likely 65F. In the day it might average around, say, 75F. Sometimes maybe as low as 70F and higher up to 85F. In Bangkok you will only notice about 1 to 3 weeks of unusually cool weather, and then it’s back to the normal heat you’re used to. It only gets hotter the further south you go.
In the north of Thailand, say Chiang Mai and Chiang Rai, it might get cold enough that you’ll see frost. On a really windy cold night it might even get as low as 40F (or at least it will feel that cold). Although many of us foreigners vacation in Thailand to flee the winter in our home country, Thais like to travel to northern Thailand to experience what cold weather is like. Even frost on the grass is a white wonder winterland for them. I’ve never heard of snow or even hail in Thailand, but perhaps it happens on very rare occasions? The southern-most regions of Thailand generally don’t have a cold season.
It does on occasion rain during cold season, like 2-3 times per month.
The Hot Season
The hot (or dry) season is from February to May. The season is as it says. Lots of hot sunny days with not much rain. But personally, the highs of 85F during the ‘cold’ season doesn’t feel that much different than the highs of 90F during the hot season. In the north east there will be little rain, and often times serious drought. In the southern provinces it’ll still rain often during this season. If you’re from Bangkok and you’re vacationing on a beach in Koh Samui during the hot season, you might swear it was rainy season.
The Rainy Season
The rainy season, or monsoon season if you prefer, is from May to October. The word for ‘rain’ in Thai is fon5 dtok2 ฝนตก. Bangkok, being located right smack in the flood delta of the largest river in Thailand, is threatened by flooding every year. It was even once referred to as the ‘Venice of the East’, before it figured out how to defend itself using dams and drainage canals.
The rainy season isn’t non-stop rain, however. Usually it’ll only rain about once a day for a few hours, and that’s it. And this will happen generally every day for the entire season. If you live outside of inner Bangkok you’ll likely experience flash floods of about a foot or so in the roads, but it’ll quickly drain away.