August in Marsh Harbour is the rainiest and the hottest month of the year. In August, the weather in Marsh Harbour is typically hot. Average daily high temperature in August is about 28 degrees above zero. On average, Marsh Harbour has 20 rainy, 8 sunny, and 3 partly cloudy 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 Marsh Harbour.