In May, the weather in Yonaguni is typically warm. Average daily high temperature in May is about 26 degrees above zero. On average, Yonaguni has 23 rainy, 4 sunny, 3 cloudy, and 1 partly cloudy day in May. The rains are usually heavy. May as well as January, February, March, and June is considered the most uncomfortable time to visit Yonaguni.