January in Passo Fundo is the rainiest month of the year. In January, the weather in Passo Fundo is typically warm. Average daily high temperature in January is about 25 degrees above zero. On average, Passo Fundo has 17 rainy and 14 sunny days in January. The rains are usually heavy. January as well as February, July, and December is considered the most uncomfortable time to visit Passo Fundo.