In December, the weather in Niagara Falls is typically cold. Average daily high temperature in December is about 2 degrees above zero. On average, Niagara Falls has 17 rainy, 11 cloudy, 2 snowy, and 1 sunny day in December. The rains are usually moderate. December as well as March, April, October, and November is considered the most uncomfortable time to visit Niagara Falls.