September in Zihuatanejo is the rainiest and the cloudiest month of the year. In September, the weather in Zihuatanejo is typically hot. Average daily high temperature in September is about 28 degrees above zero. On average, Zihuatanejo has 25 rainy, 3 cloudy, and 2 partly cloudy days in September. The rains are usually heavy. September as well as June, July, August, and October is considered the most uncomfortable time to visit Zihuatanejo.