September in Sao Leopoldo is the cloudiest month of the year. In September, the weather in Sao Leopoldo is typically warm. Average daily high temperature in September is about 21 degrees above zero. On average, Sao Leopoldo has 13 rainy, 10 sunny, 5 partly cloudy, and 2 cloudy days in September. The rains are usually heavy. September as well as January and February is considered the most uncomfortable time to visit Sao Leopoldo.