September in Chignik Lagoon is the rainiest month of the year. In September, the weather in Chignik Lagoon is typically warm. Average daily high temperature in September is about 10 degrees above zero. On average, Chignik Lagoon has 27 rainy, 2 sunny, and 1 cloudy day in September. The rains are usually heavy. September as well as April, May, June, and July is considered the most uncomfortable time to visit Chignik Lagoon.