Geography and Climate of Nepal

Geography of Nepal

The stupendous mountain pedestal of Nepal includes no fewer than eight of the world’s giants: Everest, Kanchenjunga, Lhotse, Makalu, Cho Oyu, Dhaulagiri, Manaslu and Annapurna. Mountain relief is asymmetrical, with rock strata inclined to the north, leaving steep south faces. Deep river gorges incise across the range to fall rapidly to the lower valleys. The steep slopes prevent the formation of large glaciers; a snowline varying between 16,400 feet (5,000 meters) and 19,700 feet (6,000 meters) also limit glaciation.

Below the Himalayas, running in a similar west northwest and east south direction, are two parallel ranges. Fifty-six miles (90 km) south of the great range, the Mahabharat Lekh rises to elevations of between 4,900 feet (1,500 meters) and 8,900 feet (2,700 meters). Broad tropical valleys are encased in the complicated folds, and three narrow river gorges slice through it.

Immediately south are the Siwalik Churia Hills, which rise abruptly from the Terai plains to a height of between 2,450 feet (750 meters) and 4,900 feet (1,500 meters). The hill’s dry immature soils support only a sparse population.

In the north west of the country, a fourth trans-Himalayan range defines the boundary between Nepal and Tibet. Peaks of 19,700 feet to 23,000 feet (6,000 meters to 7,000 meters) lie about 22 miles (35 km) north of the main Himalayas; their relief is less rugged, with wind-eroded landforms predominant.

Each of these mountain ranges is separated from the next by lowland or valley systems. On the south is the Terai extension of India’s vast Gangetic plain. Between 15 miles (25 km) and 25 miles (40 km) broad within the Nepalese border, the Terai’s gentle topography contrasts sharply with the rigged relief of the rest of the country.

At a slightly higher elevation, but with similar vegetation, lie the dun or inner Terai Valleys between the Siwalik Hills and the Mahabharat Lekh. Until the mid-1950s, this region was impenetrable, malaria-infested jungle. Today, with much of its rich indigenous wildlife endangered, it has become Nepal’s most populous region. Almost all of the modern industries are in the Terai, whose flatlands are ideal for growing rice and other grains.

Climate of Nepal

Summers are hot in the Terai and the dun, with temperatures often exceeding 100F (38C). Winters are considerably cooler with the temperature down to 50F (10C). Rainfall comes primarily in the June-to-September monsoon season, heaviest in the east. The strong straight saal tree, compared by some to the mahogany for its durability, and the kapok or silk cotton tree are frequently seen in Terai forests.

Between the Mahabharat Lekh and the main Himalayas lies the broad complex of hills and valleys. This pahar zone is heavily eroded by rivers and streams. It is the traditional heartland of the Nepalese people, the home of the Kathmandu Valley.

Nepal’s capital is a city of about 500,000, at once medieval and modern. Despite its 4,368-foot (1,331-meter) elevation and the snowy summits looming at its northern horizon, Kathmandu has a mild climate. Summer maximums are about 86F (30C) and mean temperatures about 50F (10C). Winters are sometimes frosty, but are dry and snowless, while summer monsoons bring substantial rain. The moderate climate permits three harvests a year in the myriad terraces and small plantings in between. Oaks and alders are often seen trees, and rhododendron and jacarandas are beautiful when in bloom.

Beyond Kathmandu, high in the mountains, thunderstorms are frequent and winter frosts limit agriculture. Nevertheless, rice is grown at 9,800 feet (3,000 meters), potatoes at 13,000 feet (4,000 meters) and barley even higher. The mountain population finds sanctuary in isolated valleys, where juniper and birch share the terrain of subalpine grasses.

There is a distinctly alpine climate in the highlands above 13,000 feet (4,000 meters). Summers are short, winters severe and dry, with high snowfall, low temperatures and strong winds. In western Nepal and northern Himalayas, there are elevated valleys reminiscent of Tibet, with broad, open profiles and arid climate—particularly where the Himalayan rain shadow blocks out the monsoon rains.