January in Moncton is the snowiest and the most freezing month of the year. In January, the weather in Moncton is typically freezing. Average daily high temperature in January is about 3 degrees below zero. On average, Moncton has 9 sunny, 8 snowy, 8 partly cloudy, 5 cloudy, and 1 rainy day in January. The snowfalls are usually heavy.