Dimapur's topography is defined by its flat plain landscape, sitting at an average elevation of about 260 meters (853 feet) above sea level. This flat terrain is geologically part of the alluvial plains formed by the Dhansiri River.
The lowest points are found along the flood plains of the Dhansiri River, which are prone to seasonal swelling during heavy monsoons. To the immediate east and southeast of the city limits, the topography begins to rise into rolling hills, marking the foothills of the Naga Hills. This transition from alluvial plains to mountainous terrain creates a distinct ecological and visual boundary just outside the city.