October in Jan Mayen is the rainiest month of the year. In October, the weather in Jan Mayen is typically cold. Average daily high temperature in October is about 4 degrees above zero. On average, Jan Mayen has 27 rainy and 4 cloudy days in October. The rains are usually heavy. October as well as January, May, August, and September is considered the most uncomfortable time to visit Jan Mayen.