August in Wilmington is the cloudiest month of the year. In August, the weather in Wilmington is typically hot. Average daily high temperature in August is about 29 degrees above zero. On average, Wilmington has 19 rainy, 5 sunny, 4 partly cloudy, and 3 cloudy days in August. The rains are usually heavy. August as well as June and July is considered the most uncomfortable time to visit Wilmington.