July in Juneau is the cloudiest and the warmest month of the year. In July, the weather in Juneau is typically warm. Average daily high temperature in July is about 12 degrees above zero. On average, Juneau has 25 rainy, 4 cloudy, and 2 sunny 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 Juneau.