December in Itumbiara is the rainiest and the cloudiest month of the year. In December, the weather in Itumbiara is typically warm. Average daily high temperature in December is about 27 degrees above zero. On average, Itumbiara has 30 rainy and 1 sunny day in December. The rains are usually heavy. December as well as January, February, March, and November is considered the most uncomfortable time to visit Itumbiara.