January in Tainan is the sunniest and the coldest month of the year. In January, the weather in Tainan is typically warm. Average daily high temperature in January is about 24 degrees above zero. On average, Tainan has 16 partly cloudy, 13 sunny, 1 rainy, and 1 cloudy day in January. The rains are usually light. January as well as February and December is considered the most comfortable time to visit Tainan.