January weather forecast in Boise

January in Boise is the coldest month of the year. In January, the weather in Boise is typically cold. Average daily high temperature in January is about zero. On average, Boise has 10 partly cloudy, 7 sunny, 6 rainy, 4 snowy, and 4 cloudy days in January. The rains are usually heavy. January as well as February, March, November, and December is considered the most uncomfortable time to visit Boise.