January in Grand Junction is the snowiest and the coldest month of the year. In January, the weather in Grand Junction is typically freezing. Average daily high temperature in January is about zero. On average, Grand Junction has 14 partly cloudy, 10 sunny, 4 cloudy, 2 snowy, and 1 rainy day in January. The snowfalls are usually light. January as well as February and December is considered the most uncomfortable time to visit Grand Junction.