May in Ust-Kamchatsk is the cloudiest month of the year. In May, the weather in Ust-Kamchatsk is typically cold. Average daily high temperature in May is about 4 degrees above zero. On average, Ust-Kamchatsk has 21 cloudy, 7 rainy, and 3 sunny days in May. The rains are usually light. May as well as January, February, September, and October is considered the most uncomfortable time to visit Ust-Kamchatsk.