In October, the weather in West Yellowstone is typically cold. Average daily high temperature in October is about 7 degrees above zero. On average, West Yellowstone has 11 sunny, 9 partly cloudy, 4 rainy, 4 cloudy, and 3 snowy days in October. The rains are usually moderate. October as well as March, April, May, and June is considered the most uncomfortable time to visit West Yellowstone.