India's climate is classified as a monsoon climate. This type of climate is mostly found in Asia's south and southeast. Despite the overall consistency of the pattern, there are regional differences in climatic conditions within the country. Let us now look at a few factors affecting the Climate of India which will be helpful in preparing Geography for the UPSC Civil service exam.

What type of Climate Does India Have?

• Although India's northern part (north of the tropic of cancer) is located in the temperate belt, its climate is very similar to that of a tropical country.
• The Himalayan ranges separate the Indian subcontinent from the rest of Asia, blocking cold air masses moving south from Central Asia.
• As a result, the northern half of India is 3°C to 8°C warmer in the winter than other areas at similar latitudes.
• The climate in the southern parts of the country resembles an equatorial dry climate during the summer due to the sun's position above the horizon.
• The north Indian plains are being influenced by a hot dry wind known as 'loo' that is blowing from the Thar, Baloch, and Iranian Deserts, raising temperatures to levels comparable to those in the country's southern regions.
• As a result, the entire Indian subcontinent south of the Himalayas can be classified as a tropical country.
• India has a typical tropical monsoon climate due to the seasonal reversal of winds in the Arabian Sea and Bay of Bengal.
• So, rather than just being tropical or half temperate, India's climate as said earlier is a tropical monsoon type (a distinct wet and dry) climate.

Factors affecting the Climate of India

• The climate of India is influenced by a variety of factors that can be divided into two categories:
• factors relating to location and relief
• factors relating to air pressure and winds

Factors Related to Location and Relief

Latitude

• The Tropic of Cancer runs east-west through the central part of India.
• As a result, the northern part of India is in the subtropical and temperate zone, while the southern part is in the tropical zone.
• As it's closer to the equator, the tropical zone has high temperatures all year with a small daily and annual range.
• Due to its distance from the equator, the area north of the Tropic of Cancer has an extreme climate with a wide daily and annual temperature range.

The Himalayan Mountains

• The Himalayas and their extensions in the north act as an effective climatic divide.
• The subcontinent is protected from the cold northern winds by the towering mountain chain, which acts as an invincible shield.
• These chilly winds blowing across central and eastern Asia, originating near the Arctic Circle.
• The Himalayas also trap monsoon winds, forcing them to disperse their moisture across the Indian subcontinent.

Distribution of Land and Water

• India is surrounded on three sides by the Indian Ocean in the south and girdled by a high and continuous mountain wall in the north.
• The water heats and cools slowly in comparison to the landmass.
• In and around the Indian subcontinent, this differential heating of land and sea creates different air pressure zones in different seasons.
• The direction of monsoon winds is reversed due to a difference in air pressure.

Distance from the Sea

• Large coastal areas have an equable climate due to their long coastline.
• Areas in India's interior are far removed from the sea's moderating influence. Thus, c Climate extremes exist in these areas.
• As a result, residents of Mumbai and the Konkan coast have only a little perception of temperature extremes and seasonal weather patterns.
• Seasonal differences in weather in the interior of the country, such as Delhi, Kanpur, and Amritsar, have an impact on all aspects of life.

Altitude

• As you get higher, the temperature drops.
• Places in the mountains are cooler than places on the plains due to thin air. Agra and Darjeeling, for example, are on the same latitude, but Agra's January temperature is 16°C, while Darjeeling's is only 4°C.

Relief

• Temperature, air pressure, wind direction and speed, amount and distribution of rainfall are all affected by India's physiography or relief.
• During June-September, the windward sides of the Western Ghats and Assam receive a lot of rain, whereas the southern plateau stays dry due to its leeward position along the Western Ghats.

Factors Related to Air Pressure and Wind

• To fully understand the differences in India's local climates, we must first understand the mechanisms of the following three factors:
• Air pressure and wind distribution on the earth's surface.
• Global weather-controlling factors and the inflow of various air masses and jet streams cause upper air circulation.
• The inflow of western cyclones, also known as disturbances, into India during the winter season and tropical depressions into India during the south-west monsoon season, resulting in favourable weather conditions for rainfall.
• The mechanism of these three factors can be understood separately by looking at the winter and summer seasons of the year.

Mechanism of Weather in Winter Season

Surface Pressure and Winds

• The weather conditions over India are generally influenced by the distribution of pressure in Central and Western Asia during the winter months.
• During the winter, a high-pressure centre forms in the region to the north of the Himalayas.
• This trough of high pressure causes a low-level flow of air from the north to the Indian subcontinent, south of the mountain range.
• The surface winds from the high-pressure center over Central Asia arrived in India as a dry continental air mass.
• The surface winds from the high-pressure center over Central Asia arrived in India as a dry continental air mass.
• Over northwestern India, these continental winds collide with trade winds.
• The position of this contact zone, on the other hand, is not stable.
• It may occasionally shift its position as far east as the middle Ganga valley, bringing dry northwestern winds to the entire region of northwestern and northern India up to the middle Ganga valley.

Jet Stream and Upper Air Circulation

• The pattern of air circulation described above is only visible near the earth's surface at the lower levels of the atmosphere.
• A different pattern of air circulation can be seen higher up in the lower troposphere, about three kilometres above the earth's surface.
• Variations in atmospheric pressure closer to the earth's surface have no bearing on the formation of upper air circulation.
• Variations in atmospheric pressure closer to the earth's surface have no bearing on the formation of upper air circulation.
• Westerly winds continue to blow across Western and Central Asia at an altitude of 9-13 km from west to east.
• These winds blow across Asia, roughly parallel to the Tibetan highlands, at latitudes north of the Himalayas. Jet streams are what they're called.
• In the path of these jet streams, the Tibetan highlands act as a barrier.
• Jet streams become bifurcated as a result.
• One of its branches blows north of the Tibetan highlands, while the other blows east of the Himalayas and south of the Tibetan highlands.
• In February, it has a mean position of 25°N at a pressure level of 200-300 mb.
• This southern branch of the jet stream is thought to have a significant impact on India's winter weather.

Western Cyclonic Disturbance and Tropical Cyclones

• The westerly jet stream brings cyclonic disturbances from the west and northwest into the Indian subcontinent during the winter months.
• The arrival of these cyclone disturbances is usually preceded by an increase in the prevailing night temperature.
• Tropical cyclones form over the Indian Ocean and the Bay of Bengal.
• The coasts of Tamil Nadu, Andhra Pradesh, and Odisha were hit by tropical cyclones with high wind speeds and heavy rainfall.
• Because of the high wind speeds and torrential rain that accompany them, the majority of these cyclones are extremely destructive.

Mechanism of Weather in Summer Season

Surface Pressure and Winds

• The wind circulation over the subcontinent undergoes a complete reversal at both the lower and upper levels as summer approaches and the sun shifts northwards.
• By the middle of July, the low pressure belt near the surface [known as the Inter Tropical Convergence Zone (ITCZ)] shifts northwards, roughly parallel to the Himalayas between 20° and 25° north latitude.

• The westerly jet stream leaves the Indian subcontinent by this time.
• In fact, meteorologists have discovered a link between the equatorial trough northward shift and the withdrawal of the westerly jet stream from over the North Indian Plain.
• Since this ITCZ is a low-pressure zone, it attracts winds from all directions.
• After crossing the equator, the maritime tropical air mass (mT) from the southern hemisphere rushes to the low pressure area in a general southwesterly direction.
• The southwest monsoon is a term used to describe a moist air current.

Jet Streams and Upper Air Circulation

• The above-mentioned pressure and wind patterns are only formed at the troposphere level.
• In June, an easterly jet stream passes over the southern part of the Peninsula at a maximum speed of 90 kilometres per hour.
• It is confined to 15oN latitudes in August, and up to 22o N latitudes in September.
• In the upper atmosphere, easterlies normally do not extend north of 30o N latitude.

Easterly Jet Stream and Tropical Cyclones

• Tropical depressions are navigated into India by the easterly jet stream.
• The distribution of monsoon rainfall over the Indian subcontinent is influenced by these depressions.
• The areas of the highest rainfall in India are the tracks of these depressions.
• The frequency with which these depressions pass through India, as well as their direction and intensity, all influence the rainfall pattern during the southwest monsoon season.

Conclusion

India, which is ranked fourth on the list of countries most affected by climate change in 2015, is experiencing significant effects as a result of climate change. Despite having 17% of the world's population, the country emits 7% of global emissions. The temperature rises on the Tibetan Plateau are causing Himalayan glaciers to retreat, putting the Ganges, Brahmaputra, Yamuna, and other major rivers' flow rates in jeopardy. According to a report published by the World Wide Fund for Nature (WWF) in 2007, the Indus River may run dry for the same reason. Heat waves are becoming more frequent and powerful in India as a result of climate change.

FAQs

Q1: What are the primary factors affecting the climate of India?

Q2: How does latitude affect the climate of India?

Q3: What role do the Himalayas play in shaping India's climate?

Q4: How does altitude influence the climate of India?

Q5: How do monsoons affect the Indian climate?

MCQs

1. Which of the following is the primary factor influencing the seasonal variation in rainfall in India?

a) Latitude

b) Ocean currents

c) Monsoon winds

d) Altitude

2. The Tropic of Cancer passes through which of the following states, affecting its climate?

a) Kerala

b) Rajasthan

c) Tamil Nadu

d) Himachal Pradesh

3. How does the proximity to the sea affect the climate of coastal regions in India?

a) It leads to extreme temperature variations

b) It moderates temperature variations

c) It decreases rainfall

d) It causes cold waves

4. What is the primary reason for the cold desert climate in Ladakh?

a) Low altitude

b) Distance from the equator

c) Rain-shadow effect of the Himalayas

d) Proximity to the sea

5. Which ocean current affects the climate along India's western coast?

a) Gulf Stream

b) Kuroshio Current

c) Agulhas Current

d) Somali Current

GS Mains Questions and Model Answers

Q1: Discuss the role of the Himalayas in influencing the climate of India.

Answer: The Himalayas play a crucial role in shaping the climate of India by acting as a barrier that influences both temperature and precipitation. The massive mountain range blocks cold winds from Central Asia, keeping northern India warmer during winter. This helps maintain a temperate climate in the northern plains, which would otherwise experience severe cold. The Himalayas also play a significant role in influencing the Indian monsoon system. The southwest monsoon winds, which bring the majority of India's rainfall, are intercepted by the Himalayas, causing orographic rainfall on the windward side. This results in heavy rainfall in regions like Assam and Meghalaya. On the leeward side, the mountains create a rain-shadow effect, leading to arid conditions in places like Ladakh. Therefore, the Himalayas are pivotal in moderating India’s climate, affecting both temperature patterns and precipitation distribution.

Q2: Analyze the impact of monsoons on the agricultural economy of India.

Answer: Monsoons are the lifeblood of India's agricultural economy, as they provide the majority of the water required for farming, especially in rain-fed regions. The southwest monsoon, which occurs from June to September, contributes about 70-80% of India's annual rainfall, essential for the cultivation of staple crops like rice, wheat, and pulses. A timely and adequate monsoon ensures a good harvest, boosts rural incomes, and supports food security. Conversely, monsoon failures or uneven distribution of rainfall can lead to droughts, crop failure, and a decline in agricultural output, adversely affecting the economy. The dependence on monsoons also makes Indian agriculture vulnerable to climate variability and necessitates better irrigation infrastructure and water management to mitigate the risks associated with erratic monsoon patterns.

Q3: Evaluate how latitude and altitude combine to create climatic diversity in India.

Answer: Latitude and altitude are two major factors contributing to the climatic diversity of India. The country's location between the Tropic of Cancer and the Equator leads to a wide range of temperatures, with tropical and subtropical climates in the southern and central regions, and temperate climates in the northern regions. Areas near the equator, like Kerala and Tamil Nadu, experience tropical monsoon climates, while states like Rajasthan and Gujarat, situated near the Tropic of Cancer, have hot desert climates. Altitude further adds to this diversity; as elevation increases, temperatures drop, creating cooler climates in mountainous regions like the Himalayas and Western Ghats. For instance, the high-altitude regions of Jammu & Kashmir and Himachal Pradesh experience alpine and tundra climates. Together, latitude and altitude result in a variety of climatic zones across India, from tropical rainforests to snow-capped mountains, supporting diverse ecosystems and human activities.

Previous Year Questions on  Factors affecting the Climate of India

1. UPSC CSE 2019

Question: Discuss the factors affecting the distribution of rainfall in India. 

Answer: The distribution of rainfall in India is influenced by several factors, including the monsoon winds, the presence of mountain ranges, proximity to the sea, and local geographical features. The southwest monsoon is the primary source of rainfall, bringing moisture-laden winds from the Indian Ocean to the subcontinent. Areas along the Western Ghats and the northeastern regions receive heavy rainfall due to orographic lifting, where the winds are forced to ascend, causing condensation and precipitation. In contrast, regions in the rain-shadow areas, like the Deccan Plateau and parts of Ladakh, receive much less rainfall. Proximity to the sea also affects rainfall, with coastal areas experiencing more consistent and moderate rainfall, while inland regions see more variability. Localized factors such as convectional currents and cyclonic disturbances also contribute to the variability of rainfall across different parts of India.

2. UPSC CSE 2020

Question: Analyze the impact of latitude, altitude, and monsoons on the climate of India.

Answer: Latitude, altitude, and monsoons are key factors shaping the climate of India. India's latitudinal extent from 8°N to 37°N places it in both tropical and subtropical zones, leading to a range of climatic conditions from hot and humid in the south to temperate in the north. Altitude further influences the climate, as temperatures drop with increasing elevation. For example, the high-altitude regions of the Himalayas experience alpine and tundra climates, while the plains have hotter and more arid conditions. Monsoons, particularly the southwest and northeast monsoons, are the dominant climatic factors that bring seasonal rainfall to the country. The southwest monsoon, which occurs from June to September, provides the majority of India's annual rainfall, affecting agriculture, water resources, and livelihoods. The interplay of latitude, altitude, and monsoons creates significant climatic diversity across the country, ranging from tropical rainforests to arid deserts and snow-covered mountains.