What would you like to know about the weather in Thailand?
December is high to peak season in Thailand and one of the reasons that is the case is because the weather is brilliant. Lots of sunshine down south, little rain and the temperatures are comfortable without being scalding or freezing.
To be honest the entire country is all very good. You've got relatively moderate temperatures across the entire country and very little to no rain. Underwater visibility is great, making December a great time for diving around Thailand. If anything, the main concern, if you want to call it that, is that the country will be filling up as December and January are peak season – booking your accommodation in advance can be prudent.
As already mentioned, great weather across the country makes all the islands pretty good. The classic Thai islands such as Phuket, Ko Lanta and Ko Phi Phi on the west coast, Ko Samui, Ko Pha Ngan and Ko Tao in the southern Gulf and Ko Samet, Ko Chang and Ko Kut in the east, will all be busy and deservedly so.
If you're planning a stay on Ko Phi Phi or Ko Lipe in southwest Thailand over the Christmas and New Year period, having a reservation in advance would be prudent as these two are traditionally at near capacity at this time of the year.
You shouldn't run into any rain whatsoever in Bangkok in December. Temperatures will swing between low 20s and low 30s Celsius and you can expect a lot of clear blue skies. Bangkok at its best.
Like Bangkok and Central Thailand, Ko Chang and the surrounding islands are lovely in December. Very little rain, with plenty of sunshine and comfortable mid-range temperatures. Crowding will become a bit of an issue as things build up towards Christmas and New Year.
Chiang Mai in December sees little rain and comfortable, almost cool daytime temperatures. Evenings can be cold and if you're trekking you will need at least a long-sleeved top — locals will be running around in leather jackets and 52 layers. A great time to explore Chiang Mai and beyond.
As with Northern and Central Thailand, temperatures will be about as moderate as it gets in northeast Thailand — even a bit chilly in the evenings — and they'll be little rain to speak of.
The only region that sees much rain in December, the Gulf Coast of Thailand sees a bit of rain — expect some rain every other day — but between the rain you'll get decent blasts of sunshine to help you recuperate. Despite the rain, December can be very busy, especially on Ko Tao and Ko Pha Ngan.
More glorious weather — and the crowds flock to it. In December on Thailand's west coast you can expect a lot of sunshine with just the very occasional shower. The weather is definitely better on this coast than the Gulf Coast — though not as good as on Ko Chang. Some islands, like Ko Phi Phi are packed to the rafters in December. A fine choice.
Follow the links below for a Thailand weather summary for each month of the year.