September in Havana is the rainiest month of the year. In September, the weather in Havana is typically hot. Average daily high temperature in September is about 29 degrees above zero. On average, Havana has 18 rainy, 9 sunny, 2 partly cloudy, and 1 cloudy day in September. The rains are usually heavy. September as well as June, July, August, and October is considered the most uncomfortable time to visit Havana.