January in Montevideo is the warmest month of the year. In January, the weather in Montevideo is typically warm. Average daily high temperature in January is about 27 degrees above zero. On average, Montevideo has 14 sunny, 8 partly cloudy, 7 rainy, and 2 cloudy days in January. The rains are usually heavy. January as well as April and December is considered the most comfortable time to visit Montevideo.