Weather in Thailand in January
Hot and wet or hot and dry?
January is peak season in Thailand and there is a reason for that — the weather is great. Both the Gulf and Andaman coasts will be seeing a lot of sunshine with little to very infrequent rain. Temperatures will oscillate around the low 20s to low 30s mark.
Bangkok and Central Thailand
Bangkok and Central Thailand will be relatively cool and as with the south, expect very little, if any, rain. The evenings may even be slightly cool.
Temperatures will be around the same as Bangkok and Central Thailand, though there will be a little more rain — perhaps 3 to 4 days of rain in the month. Despite the slight extra rain, this is one of the best times of the year weather-wise to visit the eastern islands like Ko Chang and Ko Kut.
The climate in Northern Thailand is lovely this time of year. Evenings, especially in the far north will be chilly while daytime temperatures will have a wide range from the low teens to the high twenties. Those going trekking will want to check that blankets are a part of the package! Don't be surprised if you see no rain at all in January.
The Northeast's weather in January is really an extension of Central Thailand, albeit a little cooler come the evenings. Expect little to no rain. This is a good time to visit the northeast.
On the Gulf Islands and the southeast coast, expect temperatures in the mid twenties. You will have some rain — especially in the provinces of Surat Thani (including Ko Samui, Ko Pha Ngan and Ko Tao) and Nakhon Si Thammarat. The northern coast though, from Chumphon north is far drier.
January is one of the best months of the year weather-wise to visit the Andaman Coast of Thailand centred around Phuket and Trang. It is one of the driest months of the year (though there will be a little rain) and the temperature sits around the mid 20s to low 30s range.