In September, the weather in Leukerbad is typically cold. Average daily high temperature in September is about 10 degrees above zero. On average, Leukerbad has 14 rainy, 8 sunny, 6 partly cloudy, and 2 cloudy days in September. The rains are usually heavy. September as well as April, May, June, and July is considered the most uncomfortable time to visit Leukerbad.