December in Fremantle is the windiest month of the year. In December, the weather in Fremantle is typically warm. Average daily high temperature in December is about 25 degrees above zero. On average, Fremantle has 26 sunny, 4 partly cloudy, and 1 rainy day in December. The rains are usually light. December as well as March, April, October, and November is considered the most comfortable time to visit Fremantle.