January in Rio de Janeiro is the cloudiest month of the year. In January, the weather in Rio de Janeiro is typically hot. Average daily high temperature in January is about 31 degrees above zero. On average, Rio de Janeiro has 21 rainy, 4 cloudy, 3 sunny, and 3 partly cloudy days in January. The rains are usually heavy. January as well as February, March, November, and December is considered the most uncomfortable time to visit Rio de Janeiro.