October in Otaru is the rainiest month of the year. In October, the weather in Otaru is typically warm. Average daily high temperature in October is about 14 degrees above zero. On average, Otaru has 17 rainy, 7 partly cloudy, 6 sunny, and 1 cloudy day in October. The rains are usually heavy. October as well as March, April, May, and November is considered the most uncomfortable time to visit Otaru.