India, covering 1,269,338 square miles (3,287,590 square kilometers), is roughly one-third the size of the United States. A small section of the Himalaya Mountains lies in the disputed territories of the north. The Ganges Plain below is fertile and densely populated. South of the plain is the Deccan Plateau. About half of the country is under cultivation and a little less than one-fourth is forested. Most of the country experiences three basic seasons: hot summer (March–May), rainy (June–September), and cool winter (October–February). Temperatures rarely go below 40°F (4°C) in January or reach above 100°F (40°C) during the summer. Variations exist according to region and elevation. Floods, droughts, and earthquakes are common.

The most striking element of Indian geography is the natural barrier formed by the mountain ranges in the north of India. The central mountain range, passing across in the shape of a sword near the northern edge of the Indian subcontinent, is the Great Himalayas. These northern mountains, which are less of a barrier in the west, have naturally isolated India from its neighbors.

All along the southern edge of this great mountain wall are rich soils that are generously rained on; even though this region lies in the temperate zone, it is lush and subtropical. To the south are the extensive flood plains of the Indus River in the west and the Ganges in the east. With rich soil renewed every year by river flooding and with generous summer rains, these plains in the north are among the richest agricultural areas in the world. It was here that Indian civilization first arose, in the fertile flood plains adjoining the Indus River

The southern portion of India is a large peninsula with a forbidding mountain range all along the western coast and a large flat plateau called the Deccan in the center of the sub-continent. The eastern coast is flat land and affords many opportunities for harbors; from this area Indian culture had the widest contacts with foreign peoples. The western portion, however, being walled from the sea and hard to reach by land.