August in Fukushima is the warmest month of the year. In August, the weather in Fukushima is typically warm. Average daily high temperature in August is about 25 degrees above zero. On average, Fukushima has 24 rainy, 5 sunny, and 2 cloudy days in August. The rains are usually heavy. August as well as January, February, March, and July is considered the most uncomfortable time to visit Fukushima.