September in Lillehammer is the windiest month of the year. In September, the weather in Lillehammer is typically warm. Average daily high temperature in September is about 11 degrees above zero. On average, Lillehammer has 13 rainy, 7 partly cloudy, 6 cloudy, and 4 sunny days in September. The rains are usually heavy. September as well as March, April, May, and June is considered the most uncomfortable time to visit Lillehammer.