Indian Agricultural: Growth, Generation, Policy & Problem Indian Agricultural | Page 50

Pg.no. 49
are carried towards India by the subtropical westerlies, which are the prevailing winds blowing at
North India's range of latitude. Once their passage is hindered by the Himalayas, they are unable to
proceed further, and they release significant precipitation over the southern Himalayas.
There is a huge variation in the climatic conditions of Himachal Pradesh due to variation in altitude
(450–6500 metres). The climate varies from hot and subtropical humid (450–900 meters) in the
southern low tracts, warm and temperate (900–1800 metres), cool and temperate (1900–2400
metres) and cold glacial and alpine (2400–4800 meters) in the northern and eastern elevated
mountain ranges. By October, nights and mornings are very cold. Snowfall at elevations of nearly
3000 m is about 3 m and lasts from December start to March end. Elevations above 4500 m support
perpetual snow. The spring season starts from mid February to mid April. The weather is pleasant
and comfortable in the season. The rainy season starts at the end of the month of June. The
landscape lushes green and fresh. During the season streams and natural springs are replenished.
The heavy rains in July and August cause a lot of damage resulting in erosion, floods and landslides.
Out of all the state districts, Dharamsala receives the highest rainfall, nearly about 3,400 mm (134 in).
Spiti is the driest area of the state, where annual rainfall is below 50 mm. The five Himalayan states
(Jammu and Kashmir in the extreme north, Himachal Pradesh, Uttarakhand, Sikkim and Arunachal
Pradesh) along Northern West Bengal experience heavy snowfall, Manipur and Nagaland are not
located in the Himalayas but experience occasional snowfall; in Jammu and Kashmir, blizzards occur
regularly, disrupting travel and other activities.
The rest of North India, including the Indo-Gangetic Plain and Madhya Pradesh almost never receives
snow. Temperatures in the plains occasionally fall below freezing, though never for more than one or
two days. Winter highs in Delhi range from 16 to 21 °C (61 to 70 °F). Nighttime temperatures average
2–8 °C (36–46 °F). In the plains of Punjab, lows can fall below freezing, dropping to around −3 °C (27
°F) in Amritsar. Frost sometimes occurs, but the hallmark of the season is the notorious fog, which
frequently disrupts daily life; fog grows thick enough to hinder visibility and disrupt air travel 15–20
days annually. In Bihar in middle of the Ganges plain, hot weather sets in and the summer lasts until
the middle of June. The highest temperature is often registered in May which is the hottest time. Like
the rest of the north, Bihar also experiences dust-storms, thunderstorms and dust raising winds during
the hot season. Dust storms having a velocity of 48–64 km/h (30–40 mph) are most frequent in May
and with second maximum in April and June. The hot winds (loo) of Bihar plains blow during April and
May with an average velocity of 8–16 km/h (5–10 mph). These hot winds greatly affect human comfort
during this season. Rain follows. The rainy season begins in June. The rainiest months are July and
August. The rains are the gifts of the southwest monsoon. There are in Bihar three distinct areas
where rainfall exceeds 1,800 mm (71 in). Two of them are in the northern and northwestern portions
of the state; the third lies in the area around Netarhat. The southwest monsoon normally withdraws
from Bihar in the first week of October. Eastern India's climate is much milder, experiencing
moderately warm days and cool nights. Highs range from 23 °C (73 °F) in Patna to 26 °C (79 °F) in
Kolkata (Calcutta); lows average from 9 °C (48 °F) in Patna to 14 °C (57 °F) in Kolkata. In Madhya
Ramesh Kumar P