January in Hamilton is the snowiest, the windiest, the cloudiest, and the most freezing month of the year. In January, the weather in Hamilton is typically freezing. Average daily high temperature in January is about 2 degrees below zero. On average, Hamilton has 13 snowy, 13 cloudy, 2 rainy, 2 sunny, and 1 partly cloudy day in January. The snowfalls are usually moderate.