August in Ciudad Valles is the hottest month of the year. In August, the weather in Ciudad Valles is typically hot. Average daily high temperature in August is about 31 degrees above zero. On average, Ciudad Valles has 17 rainy, 8 sunny, and 6 partly cloudy days in August. The rains are usually heavy. August as well as May, June, July, and September is considered the most uncomfortable time to visit Ciudad Valles.