Climate Of India

Climate Of India- India has diverse climatic conditions. There are sharp variations in its temperature and precipitation from one place to another and season to season. The temperature touches as high as 55°C in the western deserts during the summer season whereas it drops down as low as – 45°C in Leh during the winter season. Similarly, variations are noticeable not only in the type of precipitation but also in its amount.

Climate Of India – Factors affecting Indian Climate

1. Latitude:

India lies between 8°N and 37°N latitudes. The Tropic of Cancer passes through the middle of India. While the southern part lies in the tropical zone, the northern part falls in the sub-tropical zone. As such temperature remains quite high during summer season all over the country except in the areas of high altitudes. But during winter, temperature falls considerably in the northern plains and records below freezing point in many parts of the Himalayan belt. However, it is low to moderate in rest of the country. Thus, India by and large enjoys a hot tropical climate.

2. Himalayan Mountains:

The Himalayas are also responsible for the tropical climate of India. This high and extensive mountain system protects India from the cold winds from the north. At the same time, the Himalayas obstruct the southwesterly monsoon thereby causing heavy rainfall in the Northern Plains of India.

3. Distance from the sea :

The Peninsular character of southern India also has its climatic influence. With along coastline, we have a large coastal area enjoying the equable influence of the sea. However, a large area in the northern part of the country lies too far away from the sea. Here the climate is continental. Compare the seasonal and daily range of temperature between the places on the coast of India such as Chennai, Mangalore, Mumbai and Kolkata on the one hand and the places like Delhi, Jaisalmer and Jaipur on the other. The places located away from the coast have a far larger daily and seasonal range of temperature.

4. Altitude:

Relief of land is also an important factor affecting the climatic conditions in various parts of India. A higher altitude is responsible for lower temperatures not only in the northern mountainous region but also in the Peninsular Plateau region. Hill stations of the Peninsular Plateau region, such as Ootacomund (Ooty), though quite close to the Equator, have a rather cool climate. However, the temperatures in the Himalayan region are still lower due to both a greater distance from the Equator and a higher altitude.That is why the hill stations are numerous in the Himalayas.

5. Conditions in the regions surrounding India

Temperature and pressure conditions in East Africa, Iran, Central Asia and Tibet determine the strength of the monsoon and the occassional dry spells.

6. Jet Streams:

Jet stream is a band of fastmoving air currents in the upper layers of the atmosphere. These fast moving currents also have an impact on the arrival or departure of the monsoons.

7. Varied relief:

Relief plays an important role in the climatic condition of the continent.The Western Ghats rise abruptly like a wall from the Western Coastal plains more or less parallel to the coastline. This wall like mountain range forces the moist laden South-West monsoons from the Arabian Sea to ascent the slope thereby giving heavy rainfall in the West Coastal Plain and still heavier rainfall on the western slopes of the Western Ghats, i.e., the windward side of the mountain range.

Climate Of India – DISTRIBUTION OF RAINFALL IN INDIA

Distribution of Rainfall:

The distribution ofrainfall depends on the following factors:

1. The relief.

2. Direction of the moisture-laden winds.

3. The path of cyclonic depression determined by pressure gradient.The Indian Subcontinent can be divided into four rainfall regions:

Areas of Heavy Rainfall.

Over 200 cm a year (in some parts the annual rainfall exceeds 400 cm) are :The western slopes of the Western Ghats, and the Western Coastal Plains of Maharashtra, Goa, Karnataka and Kerala.The southern part of Kerala gets rainfall from both the advancing monsoon, i.e., South-West Monsoon and the retreating monsoon.The southern slopes of the Eastern Himalayas, particularly the Garo, Khasi, Jaintia, Patkai, Naga and Lushai hills commonly referred to as the ‘Assam Hills’ receive heavy rainfall.

The Western Ghat Region:

The moisture-laden Arabian Sea branch of the South-West monsoon is forced to rise very high because of the high Wester Ghats. Condensation and heavy rainfall of more than 200 cm take place on the windward side of the Western Ghats. The amount received decreases northwards and eastwards – Thiruvananthapuram 325 cm, Goa 300 cm, Mumbai 200 cm (on the west coast); Chennai 40 to 50 cm (east coast).The Arabian Sea branch of the South-West monsoon, after shedding heavy rainfall on the windward side (Mangalore, Goa, Mumbai) of the Western Ghats, descends on the leeward side. By this time very little moisture is left. Therefore, low rainfall is experienced in Pune, Hyderabad, Bengaluru and Chennai.

The Assam Region :

The warm moisture-laden South-West monsoon winds from the Bay of Bengal branch enter into a funnel-shaped depression, but not much moisture is lost as it is a humid delta region. The high Himalayas and Assam Hills force them to rise very high, resulting in heavy rainfall (more than 1,250 cm). Cherrapunji and Mawsynram situated on the windward slopes of the Khasi-Jaintia range, receive more 1,250 cm whereas Shillong on leeward side of the Shillong plateau is the rain shadow area and recieves only 250 cm.The reason for this variation in rainfall is quite obvious. The Bay of Bengal branch of the South-West monsoon gives heavy rainfall to the Assam region. The high Himalayas cause rainfall which gradually decreases towards Jammu and Kashmir.

Regions of Moderate Rainfall (100-200 cm a year):

The middle Ganga valley in Bihar, Jharkhand, Bengal, Odisha, some parts of the Western Ghats, eastern Maharastra, Madhya Pradesh, Chhattisgarh, the northern part of Andhra Pradesh and the southern part of Tamil Nadu receive moderate rainfall.

Regions of Scanty Rainfall(50-100 cm a year)

The areas of upper Ganga valley, eastern Rajasthan, parts of Punjab and Haryana and Jammu and Kashmir receive scanty rainfall. The monsoon duration in these areas is very short as these areas are last to receive the rainfall and first to see it retreat. Large parts of the Deccan Plateau and the Indus Plain also receive scanty rainfall.

Desert and Semi-Desert regions (less than 50 cm a year):

These are the northern parts of Kashmir, southern Punjab, parts of Haryana, western Rajasthan, Thar, the Kutch Peninsula, and the rain shadow regions of the Western Ghats.