January in Shirahama is the coldest month of the year. In January, the weather in Shirahama is typically cold. Average daily high temperature in January is about 2 degrees above zero. On average, Shirahama has 16 partly cloudy, 10 sunny, 4 rainy, and 1 cloudy day in January. The rains are usually moderate. January as well as February, March, April, and December is considered the most uncomfortable time to visit Shirahama.