December in Roswell is the cloudiest month of the year. In December, the weather in Roswell is typically warm. Average daily high temperature in December is about 11 degrees above zero. On average, Roswell has 11 rainy, 9 sunny, 8 partly cloudy, and 3 cloudy days in December. The rains are usually heavy. December as well as January, February, and August is considered the most uncomfortable time to visit Roswell.