July in Tromsø is the warmest month of the year. In July, the weather in Tromsø is typically warm. Average daily high temperature in July is about 13 degrees above zero. On average, Tromsø has 21 rainy, 4 sunny, 4 cloudy, and 2 partly cloudy days in July. The rains are usually heavy. July as well as April, May, June, and August is considered the most uncomfortable time to visit Tromsø.