December in Tangará da Serra is the rainiest month of the year. In December, the weather in Tangará da Serra is typically hot. Average daily high temperature in December is about 29 degrees above zero. On average, Tangará da Serra has 30 rainy and 1 sunny day in December. The rains are usually heavy. December as well as January, February, March, and April is considered the most uncomfortable time to visit Tangará da Serra.