As Wladimir Koppen climate classification, Irkutsk has Dwc classification which mean Monsoon-influenced subarctic climate; coldest month averaging below 0 °C (and 1–3 months averaging above 10 °C . At least ten times as much rain in the wettest month of summer as in the driest month of winter (alternative definition is 70% or more of average annual precipitation is received in the warmest six months).