August in San Luis Potosí is the windiest month of the year. In August, the weather in San Luis Potosí is typically warm. Average daily high temperature in August is about 21 degrees above zero. On average, San Luis Potosí has 11 rainy, 8 sunny, 8 partly cloudy, and 4 cloudy days in August. The rains are usually heavy. August as well as July and September is considered the most uncomfortable time to visit San Luis Potosí.