In September, the weather in Santiago de Querétaro is typically warm. Average daily high temperature in September is about 25 degrees above zero. On average, Santiago de Querétaro has 15 rainy, 6 partly cloudy, 5 sunny, and 4 cloudy days in September. The rains are usually heavy. September as well as June, July, and August is considered the most uncomfortable time to visit Santiago de Querétaro.