January in Cary is the snowiest and the coldest month of the year. In January, the weather in Cary is typically warm. Average daily high temperature in January is about 10 degrees above zero. On average, Cary has 10 sunny, 9 partly cloudy, 8 rainy, 3 cloudy, and 1 snowy day in January. The rains are usually heavy. January as well as June, July, August, and December is considered the most uncomfortable time to visit Cary.