September in Mexico is the sunniest month of the year. In September, the weather in Mexico is typically warm. Average daily high temperature in September is about 26 degrees above zero. On average, Mexico has 16 sunny, 8 rainy, 4 cloudy, and 2 partly cloudy days in September. The rains are usually heavy. September as well as {{month_nom: February}}, and {{month_nom: February}} is considered the most comfortable time to visit Mexico.