January in Boston is the snowiest, the windiest, and the coldest month of the year. In January, the weather in Boston is typically cold. Average daily high temperature in January is about 1 degree above zero. On average, Boston has 14 partly cloudy, 11 sunny, 3 rainy, 2 snowy, and 1 cloudy day in January. The rains are usually heavy. January as well as February, March, and December is considered the most uncomfortable time to visit Boston.