July in Longyearbyen is the cloudiest month of the year. In July, the weather in Longyearbyen is typically cold. Average daily high temperature in July is about 4 degrees above zero. On average, Longyearbyen has 24 cloudy and 7 rainy days in July. The rains are usually light. July as well as January, February, March, and June is considered the most uncomfortable time to visit Longyearbyen.