January in Boston is the snowiest and the coldest month of the year. In January, the weather in Boston is typically cold. Average daily high temperature in January is about 2 degrees above zero. On average, Boston has 11 sunny, 9 partly cloudy, 4 rainy, 4 cloudy, and 3 snowy days in January. The rains are usually heavy. January as well as February, March, April, and November is considered the most uncomfortable time to visit Boston.