December in Incheon is the windiest month of the year. In December, the weather in Incheon is typically cold. Average daily high temperature in December is about 1 degree above zero. On average, Incheon has 15 sunny, 13 partly cloudy, 2 rainy, and 1 cloudy day in December. The rains are usually moderate. December as well as January, February, March, and July is considered the most uncomfortable time to visit Incheon.