July in Ust-Ilimsk is the warmest month of the year. In July, the weather in Ust-Ilimsk is typically warm. Average daily high temperature in July is about 22 degrees above zero. On average, Ust-Ilimsk has 11 partly cloudy, 10 cloudy, 6 sunny, and 4 rainy days in July. The rains are usually moderate. July as well as June is considered the most comfortable time to visit Ust-Ilimsk.