December in Ribeirao Preto is the rainiest and the cloudiest month of the year. In December, the weather in Ribeirao Preto is typically warm. Average daily high temperature in December is about 27 degrees above zero. On average, Ribeirao Preto has 28 rainy and 3 sunny days in December. The rains are usually heavy. December as well as January, February, March, and November is considered the most uncomfortable time to visit Ribeirao Preto.