The climate of Northern Italy is mainly humid subtropical (Köppen "Cfa"), especially in the plains. Winter in Northern Italy is normally long, relatively dry and rather cold. In addition, there is a high seasonal temperature variation between summer and winter. In the hills and mountains, the climate is humid continental (Köppen "Dfb"). In the valleys it is cold but usually with low humidity, while it can be severely cold above , with copious snowfalls. The coastal areas of Liguria generally fit the Mediterranean climate profile. In the Alpine foothills, characterised by an Oceanic climate (Köppen "Cfb"), numerous lakes exercise a mitigating influence, allowing the cultivation of typically Mediterranean crops (olives, citrus fruit).