The mountainous terrain is broken by small basins or valleys, dotted with settlements and agricultural fields. The area can be divided into the northern, central and southern regions which happen to coincide with administrative boundaries (Shinwari, undated). The northern zone consists of the Bajaur and Mohmand agencies. The hills in this region form a transition zone between the Hindukush mountains, and the Piedmont and lowland basins. Here, the Jandool river and its tributaries join the Panjkora river. Towards the south, the Kabul river collects the outflow from local rivers including the Bira Darya and khwars (seasonal watercourses) such as the Gandab, Sallala and Shalman.
The central region covers the Khyber, Kurram and Orakzai agencies, and the FRs of Kohat and Peshawar. Here, the Safed Koh mountains rise from the Terimangal pass and stretch eastward, reaching an elevation of 3,600 meters. The Sikaram, at 4,760 meters, is the tallest peak in this range. The Kurram river flows north-west to south-east, entering North Waziristan below the town of Thal in the Hangu district of the KPK, and eventually joining the Indus river. In Orakzai Agency, the Khanki and Mastura streams flow to the east to meet the Bara river. The towns of Bara and Khajuri form a plains area from where the Bara river and its tributaries join the Kabul river near Peshawar. To the north of the Kabul river stand the Mullagori and Shilman hills. The fertile Bara, Khanki, Kurram and Mastura valleys contain the most extensively cultivated land in FATA.
The southern region comprises the North Waziristan and South Waziristan agencies, and the FRs of Bannu, Dera Ismail Khan, Lakki Marwat and Tank. To the south of the Safed Koh are the Sulaiman mountains and the Waziristan hills. The hills rise to an altitude of between 1,500 and 3,000 meters, and are mostly barren. Takht-i-Sulaiman, located in FR Dera Ismail Khan, is the highest peak in the Sulaiman range, at 3,487 meters. Overall drainage in this region is toward the east. The Gomal river flows in the south, while the Kurram river passes though the north. The Jandola, Kaitu and Tochi are smaller rivers in this area. The rod kohi system (flood irrigation, or torrent-spate irrigation) is commonly practiced mainly in the FR areas. The Gomal and Tochi mountain passes in the south connect Pakistan to Afghanistan.
An interesting mix of sedimentary, igneous and metamorphic rock is found in the area. The most common sedimentary formations consist of sandstone, limestone, shale and conglomerates, occurring in the south-west. Partly metamorphosed andesite, granite and gabbro make up the bulk of igneous masses. Metamorphic rocks in the area include schist, slate and marble.
The soil is derived mainly from the local weathering of bedrock, deposited by streams and rivers, though loses also occurs to some extent. Landforms in the area are varied and include piedmont, plains, valleys, gravel fans, rough broken land and gullied land. Level areas are loamy, while lowlands are slightly to strongly calcareous. The content of organic matter and available phosphorus is very low.
FATA lies on the cusp of two major climatic systems, the monsoon to the east and the Mediterranean towards the west. Most parts of FATA are arid and semi-arid, with warm summers and cool winters, although some areas in the Kurram and Orakzai agencies fall within the humid and sub-humid zone. The pattern and character of summer and winter rainfall is intermixed to such an extent that it is difficult to determine which is dominant. According to meteorological data, the area receives more winter precipitation as a result of western disturbances and some rain in the summer from the monsoon. Annual rainfall in the area varies dramatically, from 630 millimeters reported in Kurram during 2001-02, to just 88 millimeters in neighboring Khyber Agency during the same year.