In September, the weather in Kristiansund is typically warm. Average daily high temperature in September is about 14 degrees above zero. On average, Kristiansund has 18 rainy, 7 sunny, 4 partly cloudy, and 1 cloudy day in September. The rains are usually heavy. September as well as January, February, March, and April is considered the most uncomfortable time to visit Kristiansund.