January in Harrisburg is the snowiest and the coldest month of the year. In January, the weather in Harrisburg is typically cold. Average daily high temperature in January is about 1 degree above zero. On average, Harrisburg has 11 partly cloudy, 8 cloudy, 6 sunny, 5 rainy, and 1 snowy day in January. The rains are usually moderate. January as well as February, March, April, and December is considered the most uncomfortable time to visit Harrisburg.