It is 388 km (241 mi) long, and drains an area of around 25,000 km2 (9,653 sq mi). The maximum depth of the river is 4 m (13 ft).

 

     The river rises at Vrutok, a few kilometers north of Gostivar in the Republic of Macedonia. It passes through Gostivar, Skopje and into Veles, crosses the Greek border near Gevgelija, Polykastro and Axioupoli ("town on the Axiós"), before emptying into the Aegean Sea in Central Macedonia west of Thessaloniki in northern Greece.
The Vardar basin includes two-thirds of the territory of the Republic of Macedonia. The area is sometimes called "Vardar Macedonia" after the river.

   The Vardaris or Vardarec is a powerful prevailing northerly ravine wind which blows across the river valley in Greek Macedonia as well as in the Republic of Macedonia. At first it descends along the "canal" of the Vardar valley, usually as a breeze. When it encounters the high mountains that separate Greece from the Republic of Macedonia, it descends the other side, gathering a tremendous momentum and bringing cold conditions to the city of Thessaloniki and the Axios delta. Somewhat similar to the mistral wind of France, it occurs when atmospheric pressure over eastern Europe is higher than over the Aegean Sea, as is often the case in winter.