September in Sao Jose Do Rio Preto is the windiest and the hottest month of the year. In September, the weather in Sao Jose Do Rio Preto is typically hot. Average daily high temperature in September is about 31 degrees above zero. On average, Sao Jose Do Rio Preto has 21 sunny, 7 partly cloudy, and 2 rainy days in September. The rains are usually light.