August in Valdez is the rainiest month of the year. In August, the weather in Valdez is typically cold. Average daily high temperature in August is about 8 degrees above zero. On average, Valdez has 27 rainy, 3 sunny, and 1 cloudy day in August. The rains are usually heavy. August as well as May, June, July, and September is considered the most uncomfortable time to visit Valdez.