January in Curitiba is the rainiest and the cloudiest month of the year. In January, the weather in Curitiba is typically warm. Average daily high temperature in January is about 23 degrees above zero. On average, Curitiba has 28 rainy and 3 sunny days in January. The rains are usually heavy. January as well as February, March, April, and May is considered the most uncomfortable time to visit Curitiba.