January in Hiroshima is the snowiest and the coldest month of the year. In January, the weather in Hiroshima is typically cold. Average daily high temperature in January is about 6 degrees above zero. On average, Hiroshima has 13 partly cloudy, 8 rainy, 7 sunny, 2 cloudy, and 1 snowy day in January. The rains are usually heavy. January as well as February, March, June, and July is considered the most uncomfortable time to visit Hiroshima.