December in Alta Floresta is the cloudiest month of the year. In December, the weather in Alta Floresta is typically hot. Average daily high temperature in December is about 30 degrees above zero. On average, Alta Floresta has 28 rainy, 2 partly cloudy, and 1 cloudy 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 Alta Floresta.