The Orange Free State is mostly flat, because it lies in the center of the high plateau. North of the Vaal River, the Highveld becomes better watered and does not get subtropical heat. Johannesburg, in the center of the Highveld, is at 1,740 m (5,709 ft) and gets a yearly rainfall of 740 mm (29.9 in). Winters in this region are cold, although snow is rare.