December in Izmit is the cloudiest month of the year. In December, the weather in Izmit is typically warm. Average daily high temperature in December is about 10 degrees above zero. On average, Izmit has 13 rainy, 8 partly cloudy, 6 cloudy, and 4 sunny days in December. The rains are usually heavy. December as well as January, February, and March is considered the most uncomfortable time to visit Izmit.