September in Santiago de Cuba is the rainiest and the cloudiest month of the year. In September, the weather in Santiago de Cuba is typically hot. Average daily high temperature in September is about 31 degrees above zero. On average, Santiago de Cuba has 23 rainy, 3 sunny, 3 partly cloudy, and 1 cloudy day in September. The rains are usually heavy. September as well as May, June, July, and August is considered the most uncomfortable time to visit Santiago de Cuba.