The Vardar river, which flows through Skopje, is at approximately  from its source near Gostivar. In Skopje, its average discharge is 51 m3/s, with a wide amplitude depending on seasons, between 99.6 m3/s in May and 18.7 m3/s in July. The water temperature is comprised between 4.6 °C in January and 18.1 °C in July.