August in Kushiro is the rainiest and the warmest month of the year. In August, the weather in Kushiro is typically warm. Average daily high temperature in August is about 21 degrees above zero. On average, Kushiro has 15 rainy, 9 cloudy, 4 sunny, and 3 partly cloudy days in August. The rains are usually heavy. August as well as March, April, June, and November is considered the most uncomfortable time to visit Kushiro.