December in Napanee is the cloudiest month of the year. In December, the weather in Napanee is typically freezing. Average daily high temperature in December is about 1 degree above zero. On average, Napanee has 10 partly cloudy, 9 cloudy, 5 sunny, 4 snowy, and 3 rainy days in December. The snowfalls are usually moderate. December as well as February, March, April, and October is considered the most uncomfortable time to visit Napanee.