In January, the weather in Chilliwack is typically cold. Average daily high temperature in January is about 2 degrees above zero. On average, Chilliwack has 17 rainy, 5 snowy, 4 sunny, 4 cloudy, and 1 partly cloudy day in January. The rains are usually heavy. January as well as February, March, April, and May is considered the most uncomfortable time to visit Chilliwack.