Weather is probably a major factor when you plan your trip to Okushiri, but bear in mind that cheaper options are usually available when the weather isn't as good. 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.