Seasons in India
|Seasons||Indian Calender||Gregorian Calender|
Season based on Monsoon: The climate of India may be described as tropical monsoon. Even northern India, lying beyond the tropical zone, acquires a tropical touch marked by the relatively high temperatures. The large size of the country and its varied relief play a crucial role in determining the climatic variations in different part of India. But the seasonal rhythm of the monsoon is apparent throughout India. It may conveniently from the basis for dividing the year into different seasons. The most characteristic feature of the monsoon is the complete reversal of winds. It eventually leads to the alternation of seasons. India is known as the “land of the endless growing season“.
The year is divided into fours seasons:
- The Cold Weather Season: (N.E. Monsoons) The Cold weather seasons starts in January. The north-east monsoon is fully established over India this seasons. the mean January day temperature in Chennai and Calicut is about 24-25 degree C while in the northern plains it is about 10-15 degree C. In December, the sunshines directly over the Trophic of Capricorn. The landmass of Asia, including the sub-continent, cools down very rapidly. There is a high pressure over the continent. The Indian Ocean, being warmer, has a relatively low pressure.
Three Reasons For Excessive Colds in North India
- States like Punjab, Haryana and Rajasthan being far away from the moderating influence of sea experience continental climate.
- The snowfall in the nearly Himalayan ranges create cold wave situation.
- Around February, the cold winds coming from Caspean Sea and Turkmenistan bring cold wave along with frost and fog over N. Western part of India.
N.E.Trade Winds (prevailing winds in the tropical Latitudes), blow, land to sea. These winds, being off shore do not give rain. In this season western disturbances bring light rainfall, most beneficial to the rabi crop in N.W. India. This rainfall decreases towards the east and the south. The Peninsular region of India, however does not have any well-defined cold weather season. There is hardly any seasonal change in the distribution pattern of the temperature in coastal areas because of moderating influence of sea and the proximity to equator.
- The Hot Weather Season: From mid March to May the sun moves over the Equator towards tropic of Cancer. By June 21, it is directly overhead the Trophic of Cancer. In March, the highest day temperatures of about 38 degree C occur in the Deccan Plateau. Therefore,
- Peninsular India, places south of Satpuras experience temperature between 26-32 degree C.
- Central India, comprising of Delhi and Madhya Pradesh experience temperature between 40-45 degree C.
- North-West India, comprising mainly of Rajasthan has very high temperature (45 degree C), due also to features like sandy soil, direct insulation and lack of cloud cover.
Storms During the Hot Weather Season
- Mango Showers (since the rain showers are good for the mango trees) occurs along the coast of Kerala.
- Norwester/Kalbaisakhi (Dark Clouds in the month of Baisakh) occurs in Assam and West Bengal. These are thunderstorms, accompanied with strong winds are heavy rainfall. This is good for the tea crop in Assam and the jute and rice in West Bengal. In Assam these storms are called Bardoli chherha.
- Loo is the name given to the hot, dry winds that blow in the Northern Plains. It is very common in Punjab, Haryana, Western Uttar Pradesh (called “aandhi”) and Bihar.
- Blossom Shower with this shower, coffee flowers blossom in Karnataka and its nearby areas.
- The South-West Monsoon Season: This season begins in June and lasts until September. The low pressure which existed over Norther Plain is further intensified. It is strong enough to attract the moisture bearing winds from the Indian Ocean.
Facts about S.W. Monsoon
- The bulk of rainfall is received during this season in almost every part of India except Tamil Nadu.
- The amount of rainfall received depends on the relief of the region.
- The rain is unreliable and there are dry intervals.
The S.E Trade Winds from the Southern Hemisphere are drawn into India as the S.W. Monsoon Winds after they cross the Equator. Due to the triangular shape of India, the S.W.Monsoon Winds are divided into branches – the Arabian Sea Branch and the Bay of Bengal Branch.The Arabian Sea Branch: It gives very heavy rainfall, more than 200 cm, to the windward side of Western Ghats. The Deccan Plateau, which lies on the leeward side of the Western Ghats, receives less than 150 cm of rainfall. Further east, rainfall decreases for eg, Hyderabad gets less than 100 cm while Chennai gets even less than 40 cm of rainfall. It does not give much rain to Rajasthan because of Aravali Ranges lie parallel to the direction of winds and hence condensation does not occur. Therefore, Rajasthan gets less than 25 cm rainfall. These winds advance northwards, attracted to the low pressure in India. Punjab at the foothill of the Shiwalik, get Relief Rainfall.
Bay of Bengal Branch: The Bay of Bengal Branch which also blows from the southwest direction, is deflected by the Arakhan Mountains of Myanmar and the N.E. Hills of India (Garo, Khasi and Jaintia) towards genetic plain. The delta of Ganga-Brahmaputra and the wind-ward side of the N.E. Hills of India get heavy rain. For example, Cherrapunji on the windward side gets 2500 cm of rainfall, while Shillong on the leeward slope gets about 250 cm. The rainfall decreases as the winds reach the eastern Himalayas and blow westward into the Ganga Plain, attracted by the low pressure in Punjab and Rajasthan.
- The Retreating of S.W. Monsoon Season: This season lasts through October to December. The temperature in the Northern Plains begins to decrease as the Sun’s rays no longer fall directly at the Tropic of Cancer. In September, the Sun shine directly at the Equator. The low pressure over the Northern Plain is not longer strong enough to attract the Monsoon Winds into the heart of India. By the end of September, the Monsoon winds are drawn only upto Punjab, by mid-October upto the Central India and by the early November upto Souther India. Thus, the S.W. Monsoon winds seem to withdraw in stages during this season. That is why this season is known as Retreating S.W. Monsoon season.
This season is marked by cyclones in the Bay of Bengal. They hit the east coast of India and Bangladesh causing widespread damage to life, property and crops.
|Difference between the Retreating S.W. Monsoon and North East Monsoon|