January in Sao Paulo is the rainiest and the cloudiest month of the year. In January, the weather in Sao Paulo is typically warm. Average daily high temperature in January is about 27 degrees above zero. On average, Sao Paulo has 24 rainy, 3 partly cloudy, 2 sunny, and 2 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 Sao Paulo.