August in Bellevue is the sunniest month of the year. In August, the weather in Bellevue is typically hot. Average daily high temperature in August is about 28 degrees above zero. On average, Bellevue has 24 sunny, 5 partly cloudy, and 2 rainy days in August. The rains are usually moderate. August as well as September is considered the most comfortable time to visit Bellevue.