December in Hat Yai is the coldest month of the year. In December, the weather in Hat Yai is typically warm. Average daily high temperature in December is about 27 degrees above zero. On average, Hat Yai has 29 rainy, 1 sunny, and 1 cloudy day in December. The rains are usually heavy. December as well as January, April, May, and June is considered the most uncomfortable time to visit Hat Yai.