September in Emerald is the windiest month of the year. In September, the weather in Emerald is typically warm. Average daily high temperature in September is about 15 degrees above zero. On average, Emerald has 14 rainy, 8 partly cloudy, 7 sunny, 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 Emerald.