The plateau is highest in the central part, where its height above sea-level averages 1220 metres.
Plateau is rectangular in shape and it runs in the east-west direction. Different sections of this plateau are named after the tribes inhabitating them. From west to east the different sections of the Meghalaya Hills are named as the Garo Hills, the Khasi Hills and the Jaintia Hills. The people-the Garos, the Khasis and the Kacharis-are Mongoloids. The density of population was just 71 persons per square km. in 1991.
There is hot and humid climate. Mean July temperature of Shillong (1500 metres) is 21.1°C. In January mean temperature is 9.6°C. Thick clouds pass over this plateau during the summer monsoon period. This blanket of the clouds reduces the amount of heat received by the ground during day and reduces radiation of heat during night.
The slopes facing south receive very heavy rainfall. Cherrapunji (1,313 metres above sea-level) is situated near the top of the plateau where a funnel-shaped re-entrant opening wide towards the south ends. The moisture laden winds coming from the south during the rainy season enter this re-entrant and join together near Cherrapunji to cause heavy rainfall. It receives the second highest rainfall (1141.86 cm. a year) after May snarum.
The most of area of the Khasi, Jaintia and Garo hills are barren. Hence, the cultivated area is small and is just about 8.8 percent (net sown area) of the total area of Meghalaya. Rice is the dominant crop particularly in the low-level areas where water is easily available. As slopes cannot retain water, they do not produce rice. Potato is an important crop in the Khasi and the Jaintia hills. About 4000 hectares are under citrus fruits in the Khasi and Jaintia hills.