December in Mossel Bay is the windiest month of the year. In December, the weather in Mossel Bay is typically warm. Average daily high temperature in December is about 25 degrees above zero. On average, Mossel Bay has 13 sunny, 9 partly cloudy, 7 rainy, and 2 cloudy days in December. The rains are usually light. December as well as January, February, March, and April is considered the most comfortable time to visit Mossel Bay.