December in Reykyavik is the snowiest and the coldest month of the year. In December, the weather in Reykyavik is typically cold. Average daily high temperature in December is about zero. On average, Reykyavik has 15 rainy, 9 snowy, 3 sunny, 3 cloudy, and 1 partly cloudy day in December. The rains are usually heavy. December as well as January, February, March, and April is considered the most uncomfortable time to visit Reykyavik.