Climatic Features of India


Climate of India

The climate of India is described as themonsoon type. This type of climate is found mainly in the south and the Southeast Asia. Despite an overall unity in the general pattern, there are perceptible regional variations in climatic conditions within the country.


Winter season

The cold weather season begins from mid-November in northern India and stays till February. December and January are the coldest months in the northern part of India. During this season, the northeast trade winds prevail over the country. They blow from land to sea and hence, for most part of the country, it is a dry season.


Rainfall in India

Owing to the nature of monsoons, the annual rainfall is highly variable from year to year. Variability is high in the regions of low rainfall such as parts of Rajasthan, Gujarat and the leeward side of the Western Ghats. As such,while areas of high rainfall are liable to be affected by floods, areas of low rainfall are drought-prone.


Variations in Climate in Different regions of India

There are variations not only in the form and types of precipitation but also in its amount and the seasonal distribution. coastal areas experience less contrasts in temperature conditions. Seasonal contrasts are more in the interior of the country. There is decrease in rainfall generally from east to west in the Northern Plains. These variations have given rise to variety in lives of people.


Summer season

Due to the apparent northward movement of the sun, the global heat belt shifts northward. As such, from March to May, it is hot weather season in India. The influence of the shifting of the heat belt can be seen clearly from temperature recordings taken during March-May at different latitudes. In March, the highest temperature is about 38 Celsius, recorded on the Deccan plateau. In April, temperatures in Gujarat and Madhya Pradesh are around 42 Celsius. In May, temperature of 45 Celsius is common in the northwestern parts of the country. 


Distribution of rainfall

The western coast and northeastern India receive over about 400 cm of rainfall annually. However, it is less than 60 cm in western Rajasthan and adjoining parts of Gujarat, Haryana and Punjab. Rainfall is equally low in the interior of the Deccan plateau, and east of the Sahyadris.


Rainy season

This is a typical monsoon feature which begins in June and lasts till October. The formation of low pressure in the central parts of India attracts monsoon winds from the Arabian Sea and the Indian Ocean. These winds are loaded by moisture and 'burst' over the land, accompanied with strong gale. The south-west monsoons get divided into two branches and bring heavy, moderate and low rainfall in different regions.


Heavy rainfall region in India

Early in the season, the wind ward side of the Western Ghats receives very heavy rainfall, more than 250 cm. The maximum rainfall of this season is received in the north-eastern part of the country. Mawsynram in the southern ranges of the Khasi Hills receives the highest average rainfall in the world.


Seasons of India

The monsoon type of climate is characterized by a distinct

seasonal pattern. The weather conditions greatly change from one season to the

other. Four main seasons can be identified in India the cold weather season,

the hot weather season, the advancing monsoon and the retreating monsoon.


Moderate rainfall region in India

Regions with 100 to 200 cm of rainfall include major parts of Bihar, West Bengal, Orissa, Madhya Pradesh, Andhra Pradesh, and parts of other states. These areas fall under the Moderate Rainfall Region.


South west monsoon season

By early June, the low-pressure condition over the northern plains intensifies. It attracts, the trade winds of the southern hemisphere. These south-east trade winds originate over the warm subtropical areas of the southern oceans. They cross the equator and blow in a southwesterly southwesterly direction entering the Indian peninsula as the south-west monsoon. As these winds blow over warm oceans, they bring abundant moisture to the subcontinent.


Low rainfall regions in India

Regions having low rainfall (50 to 100 cm) include parts Maharashtra, Gujarat, Karnataka, Tamil Nadu, Andhra Pradesh, Madhya Pradesh, Punjab, Haryana and Western Uttar Pradesh. 


Branches of Monsoon

The monsoon arrives at the southern tip of the Indian peninsula generally by the first week of June. Subsequently, it divides into two the Arabian Sea branch and the Bay of Bengal branch. The Arabian Sea branch reaches Mumbai by 10th of June while the Bay of Bengal branch arrives in Assam in the first week of June. By mid-June the Arabian Sea branch of the monsoon arrives over Saurashtra-Kuchchh and the central part of the country. These branches of monsoon merge over the northwestern part of the Ganga plains. Delhi generally receives the monsoon showers from the Bay of Bengal branch.


Scanty rainfall regions in India

Regions having scanty rainfall (50 cm) include desert and semi-desert parts of Rajasthan, Gujarat and adjoining regions.


Retreating monsoon season

The south-west monsoon winds weaken and start withdrawing gradually during October-November. By the beginning of October, the monsoon withdraws from the Northern Plains. The months of October-November form a period of transition from hot rainy season to dry winter conditions. The retreat of the monsoon is marked by clear skies and rise in temperature.


Features of the rainfall

Main features of the rainfall in India are:
(i) There is rainfall over three months and the rest of the year is mostly dry.
(ii) The rains are mainly of relief type.
(iii) Only a small portion of the rainfall is received from sources other than the monsoon like cyclonic rainfall and convectional rainfall
(iv) The quantity and the time of occurrence of rainfall cannot be predicted as the rainfall is erratic.
(v) India has an agrarian economy depending on rainfall.


Northeast monsoon season

The maximum rainfall of the Advancing Monsoon season is received in the north-eastern part of the country. Mawsynram in the southern ranges of the Khasi Hills receives the highest average rainfall in the world. Rainfall in the Ganga valley decreases from the east to the west. Rajasthan and parts of Gujarat get scanty rainfall.


Advancing monsoon


Monsoon, unlike the trade winds, are not steady winds but are pulsating in nature. They are affected by different atmospheric conditions

encountered by it on its way over the warm tropical seas. The monsoon arrives

at the southern tip of the Indian peninsula by the first week of June.

Subsequently, it divides into two the Arabian Sea branch and the Bay of

Bengal branch. The Arabian Sea branch reaches Mumbai about ten days later on approximately

the 10th of June. This is a fairly rapid advance. The Bay of Bengal branch also

advances rapidly and arrives in Assam in the first week of June.