January in Oakville is the snowiest, the windiest, and the most freezing month of the year. In January, the weather in Oakville is typically freezing. Average daily high temperature in January is about 2 degrees below zero. On average, Oakville has 15 cloudy, 8 snowy, 3 sunny, 3 partly cloudy, and 2 rainy days in January. The snowfalls are usually moderate.