The country has a generally hot and dry climate, with desert conditions prevailing throughout much of the area. Along the western border and in a section of the north are semiarid steppelands and deserts; a subtropical climate with marked summer rainfall is found in a small section of the northeast along the Himalayan foothills; and a mountain climate that varies with altitude is found in the north.

The Indus is the chief river of Pakistan and is the nation's lifeline. It flows the length of the country and is fed by the combined waters of three of the five rivers of Punjabthe Chenab, Jhelum, and Ravi. The waters of the other two rivers, the Beas and the Sutlej, are largely withdrawn for irrigation in India. Along the Indus and its tributaries are found most of Pakistan's population, its chief agricultural areas, and its major hydroelectric power stations.

Pakistan may be divided into four geographic regionsthe plateau of W Pakistan, the plains of the Indus and Punjab rivers, the hills of NW Pakistan, and the mountains of N Pakistan. The plateau region of W Pakistan, which is roughly coextensive with Baluchistan prov., is an arid region with relatively wetter conditions in its northern sections. Numerous low mountain ranges rise from the plateau, and the Hingol and Dasht rivers are among the largest streams. Large portions of the region are unfit for agriculture, and although some cotton is raised, nomadic sheep grazing is the principal activity. Coal, chromite, and natural gas are found in this area, and fishing and salt trading are carried on along the rugged Makran coast. Quetta , the chief city, is an important railroad center on the line between Afghanistan and the Indus valley.

East of the plateau region are extensive alluvial plains, through which flow the Indus and its tributaries. The region, closely coinciding with Sind and Punjab provinces, is hot and dry and is occupied in its eastern borders by the Thar Desert. Extensive irrigation facilities, fed by the waters of the Indus system, make the Indus basin the agricultural heartland of Pakistan. A variety of crops (especially wheat, rice, and cotton) are raised there. Advances in agricultural engineering have countered the salinity problems involved in farming the Indus delta. The irrigated portions of the plain are densely populated, being the site of many of Pakistan's principal cities, including Lahore , Faisalabad (formerly Lyallpur), Hyderabad , and Multan . Karachi , the nation's chief port, is located west of the irrigated land at a site accessible to oceangoing vessels. The higher parts of the plain, in the north, as in the vicinity of Lahore, have a more humid subtropical climate.

In NW Pakistan, occupying about two thirds of North-West Frontier Province, is a region of low hills and plateaus interspersed with fertile valleys. The elevation of the region tempers the arid climate. It is a predominantly agricultural area, with wheat the chief crop; fruit trees and livestock are also raised. Peshawar and Rawalpindi , the largest cities of this area, are the only major manufacturing centers. In the northern section of the North-West Frontier Province and in the Pakistani-occupied sector of Kashmir are the rugged ranges and the high, snowcapped peaks of the Hindu Kush, Himalaya, and Karakorum mountains; Tirich Mir (25,236 ft/7,692 m) is the highest point in the country outside Kashmir

Pakistan has one of the world's most rapidly growing populations. Its people are a mixture of many ethnic groups, a result of the occupation of the region by groups passing through on their way to India. The Pathans (Pashtuns) of the northwest are a large, indigenous group that has long resisted advances by invaders and that has at times sought to establish an autonomous state within Pakistan. Baluchis, who live mainly in the southwest, have also pressed for the creation of a state that would incorporate parts of Afghanistan and Iran. Punjabis reside mainly in the northeast, and Sindhis in the southeast. Pakistan is an overwhelmingly (about 97%) Muslim country. Urdu is the official language, but Punjabi, Sindhi, Pashto, Baluchi, and Brahui are also spoken; English is common among the upper classes and in the government.

Although the death rate has been reduced by improved health standards, sickness, disease, and malnutrition are still prevalent. A widespread effort to educate the population has raised the literacy rate to about 38%. Pakistan has a substantial number of universities, including a provincial university in each of the provinces; major universities and specialized schools in Lahore, Karachi, and Faisalabad; and a central university in Islamabad.