December in Stornoway is the windiest month of the year. In December, the weather in Stornoway is typically cold. Average daily high temperature in December is about 8 degrees above zero. On average, Stornoway has 28 rainy, 2 sunny, and 1 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 Stornoway.