January in Vientiane is the sunniest month of the year. In January, the weather in Vientiane is typically warm. Average daily high temperature in January is about 26 degrees above zero. On average, Vientiane has 15 sunny, 14 partly cloudy, 1 rainy, and 1 cloudy day in January. The rains are usually moderate. January as well as December is considered the most comfortable time to visit Vientiane.