December in Thailand
In most parts of Thailand, the weather is excellent in December, making it an ideal month for family trips, relaxing beach breaks, or active vacations.
The weather on the Andaman Coast in December is pleasant and perfect for exploring the islands. The east coast also benefits from a pleasant climate, with warm temperatures and calm seas. As mentioned above, notable exceptions are Koh Samui and neighboring islands in the lower Gulf of Thailand (such as Koh Phangan and Koh Tao), where the weather can be more unstable, especially in the first half of the month. There is plenty of sunshine on these islands, but there is a risk of tropical showers.
More on : https://www.tourismethai.fr/recommandations-mensuelles/decembre/decembre-en-thailande/
