December in Milton Keynes is the windiest month of the year. In December, the weather in Milton Keynes is typically cold. Average daily high temperature in December is about 7 degrees above zero. On average, Milton Keynes has 12 rainy, 11 cloudy, 4 sunny, and 4 partly 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 Milton Keynes.