January in Okayama is the coldest month of the year. In January, the weather in Okayama is typically cold. Average daily high temperature in January is about 7 degrees above zero. On average, Okayama has 18 partly cloudy, 8 sunny, 3 rainy, and 2 cloudy days in January. The rains are usually light. January as well as February, March, July, and December is considered the most uncomfortable time to visit Okayama.