August in Roswell is the cloudiest month of the year. In August, the weather in Roswell is typically hot. Average daily high temperature in August is about 32 degrees above zero. On average, Roswell has 17 sunny, 13 partly cloudy, and 1 rainy day in August. The rains are usually light. August as well as January, June, July, and December is considered the most uncomfortable time to visit Roswell.