December in Pacifica is the coldest month of the year. In December, the weather in Pacifica is typically warm. Average daily high temperature in December is about 13 degrees above zero. On average, Pacifica has 13 sunny, 12 partly cloudy, and 6 rainy days in December. The rains are usually moderate. December as well as January, February, and March is considered the most uncomfortable time to visit Pacifica.