When you're dreaming of a stay in Okushiri, make sure that you take the year-round temperatures into account. The hottest months are usually August and September, with an average temperature of 20°C, while the coldest months are January and February, with an average of 1°C. The snowiest months in Okushiri are January, February, March and December, with each month seeing an average of 77 cm of snowfall.