August in Isle of Palms is the rainiest and the cloudiest month of the year. In August, the weather in Isle of Palms is typically hot. Average daily high temperature in August is about 29 degrees above zero. On average, Isle of Palms has 20 rainy, 10 sunny, and 1 partly cloudy day in August. The rains are usually heavy. August as well as July is considered the most uncomfortable time to visit Isle of Palms.