January in Ottawa is the snowiest and the most freezing month of the year. In January, the weather in Ottawa is typically freezing. Average daily high temperature in January is about zero. On average, Ottawa has 10 partly cloudy, 8 sunny, 7 cloudy, 4 snowy, and 2 rainy days in January. The snowfalls are usually moderate. January as well as February, March, April, and November is considered the most uncomfortable time to visit Ottawa.