The Chagai Hills are granite mountains, which, at their highest point, rise to a height of 9,367 ft (3,009m) above sea level. They stretch over an area that is approximately 175 km in length and 95 km in width.
Chagai Hills lie in an arid zone, which is outside the main monsoon belt. The Chagai Hills receive an average of 4 inches (102 mm) annually. The temperature is extreme: very hot in summer and very cold in winter. The average minimum temperature is 2.4 °C (36.3 °F) in January and the average maximum temperature is 42.5 °C (108.5 °F) in July.
Chagai Hills were not the location of Pakistan's Chagai-I nuclear tests of 28 May 1998, which were at the Ras Koh Hills, an entirely different range of hills to the south of Chagai Hills, separated from the Chagai Hills by a large valley. However, confusion may arise because widespread reporting prior to the actual explosion mentioned the Chagai Hills region, and because both the Chagai Hills and the Ras Koh Hills are situated in the Chagai District.