January in King of Prussia is the snowiest and the coldest month of the year. In January, the weather in King of Prussia is typically cold. Average daily high temperature in January is about 1 degree above zero. On average, King of Prussia has 13 partly cloudy, 8 sunny, 7 rainy, 2 cloudy, and 1 snowy day in January. The rains are usually heavy. January as well as February, March, and December is considered the most uncomfortable time to visit King of Prussia.