December in Cambridge is the sunniest month of the year. In December, the weather in Cambridge is typically cold. Average daily high temperature in December is about 7 degrees above zero. On average, Cambridge has 11 rainy, 11 partly cloudy, 6 sunny, and 3 cloudy days in December. The rains are usually moderate. December as well as January, February, March, and April is considered the most uncomfortable time to visit Cambridge.