August in Itanhaém is the sunniest month of the year. In August, the weather in Itanhaém is typically warm. Average daily high temperature in August is about 22 degrees above zero. On average, Itanhaém has 16 sunny, 10 partly cloudy, and 5 rainy days in August. The rains are usually moderate. August as well as June is considered the most comfortable time to visit Itanhaém.