August in Boca Raton is the hottest month of the year. In August, the weather in Boca Raton is typically hot. Average daily high temperature in August is about 30 degrees above zero. On average, Boca Raton has 20 rainy and 11 sunny days in August. The rains are usually heavy. August as well as June, July, September, and October is considered the most uncomfortable time to visit Boca Raton.