Location and Area
The agency with the total area of 2,296 square kilometer, is bordered in the  north  with the  Bajaur Agency,  in the  east  with the  Malakand protected area and Charsadda district, in the south-east with Peshawar district, in the south with Khyber agency and  in  the  west  with  Afghanistan.   Mohmand Agency is geographically sub divided for administrative convenience into upper and lower Mohmand areas.

Mohmand Agency is an area of rugged mountains with barren slopes.  Most of the area is mountainous, with brown rocky mountains and little vegetation. There are patches of flat plains and during the spring time the region becomes greener temporarily. This region has no rivers, canals nor rich underground water reservoirs.
Ilazai (2,716) is the highest peak near the afghan border.  Other important peaks are Yari Sar (1929 meters) and Silai of Mohmand Agency. Running water is hard to find in most of these valleys except Gandab and Shilman valleys.

The Agency has an extreme climate due to its location and terrain. The winter begins in November and lasts up to March. The temperature is extremely cold from December to February and sometimes temperature plunges below freezing point. The mean maximum and minimum temperatures in these months are in the range of 5 to 16 degrees Celsius. The summer season lasts from May to September.
Most of the rainfall is during winter season and is more predictable than rainfall at other times of the year. Due to fairly consistent rainfall, the Rabi crops have a good chance of reaching maturity, but variations in the timing and amount of precipitation create risks and lead to variable yields. The main agricultural areas in the valleys of Mohmand receive about 100 mm of average rainfall per annum.

Land Use
Land use data from 2007-08 shows that 11.5% of the total geographic area of Mohmand Agency is cultivated, while more than 82% of the land is not available for cultivation. This puts intense pressure on the available agricultural land and creates food insecurity in the agency. Due to the mountainous terrain and limited surface water resources, agriculture is on the few small plains, which are irrigated by water streams from mountains.
Forests constitute only 3% of the area of the agency. Wheat is the major crop, followed by maize and barley. Rice, grape and mustard, onion and masoor are emerging as important crops. Fruit and vegetable farming is becoming popular here and it is expected that with improved irrigation facilities the production of fruits will increase further.

Main Roads
In Mohmand the total lengths of paved roads are is around 478 km out of which 364 km are paved and 114 km are Shingled roads.

The agency is divided into seven Tehsils, Halimzai, Painiali, Safi, Upper Mohmand, Barangg Khar, Yakaghund and Ambar.