December in Yonaguni is the windiest month of the year. In December, the weather in Yonaguni is typically warm. Average daily high temperature in December is about 21 degrees above zero. On average, Yonaguni has 26 rainy, 4 sunny, and 1 cloudy day in December. The rains are usually heavy. December as well as January, February, March, and May is considered the most uncomfortable time to visit Yonaguni.