UPSC Issue at a Glance | Understanding Indian Monsoon: How it forms, what influences it and why it matters

UPSC Issue at a Glance is an initiative by UPSC Essentials aimed at streamlining your UPSC Current Affairs preparation for the prelims and mains examinations by focusing on issues making headlines. In this edition, we cover the Indian Monsoon from a broader perspective. Let’s get started.

The Reserve Bank of India’s (RBI) ‘State of the Economy’ article has cautioned that an adverse south-west monsoon, if it materialises, could weigh on the domestic growth and inflation outlook. As per the updated forecast of the India Meteorological Department (IMD) (released on May 29, 2026), the south-west monsoon (SWM) rainfall is likely to be below normal this year, it said. In this backdrop, understanding the Indian monsoon and its impact on the economy becomes crucial.

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UPSC Quiz

Indian Monsoon: Test Your Knowledge

5 questions  |  Science, Geography & Economy of the Monsoon

Q1 of 5

What causes the southwest monsoon winds to blow towards India in summer?

Cooling of land surfaces near the Himalayas Low pressure over land due to rapid heating, drawing moisture-laden sea air High pressure over the Indian Ocean pushing winds inland

In summer, land heats faster than sea, creating low pressure over India that pulls in cool, moisture-laden air from high-pressure ocean regions — this differential is the engine of the monsoon.

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Q2 of 5

Which of the following correctly describes El Nino's effect on the Indian monsoon?

It strengthens monsoon winds by cooling Pacific surface waters It causes stronger rainfall by enhancing moisture-bearing winds It weakens or delays the monsoon by warming eastern Pacific waters

During El Nino, unusually warm surface waters in the eastern Pacific disrupt moist wind flow into India, resulting in a weak or delayed monsoon and dry spells in major agricultural states.

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Q3 of 5

How is the Madden-Julian Oscillation (MJO) fundamentally different from El Nino?

MJO is stationary; El Nino moves eastward around the equator MJO is a moving system circling the equator; El Nino is stationary MJO affects only the Pacific Ocean; El Nino affects only the Indian Ocean

El Nino is a stationary Pacific phenomenon, while MJO is a travelling band of cloud, wind and pressure that circles the equator every 30-60 days at 4-8 m/s and can enhance Indian monsoon rainfall in a favourable phase.

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Q4 of 5

What does a positive Indian Ocean Dipole (IOD) indicate for India's monsoon?

Below-normal rainfall due to cooler western Indian Ocean Minimal impact on monsoon patterns More rainfall due to warmer western Indian Ocean relative to the east

IOD measures sea surface temperature difference between western and eastern Indian Ocean. A positive IOD — warmer west — drives more rainfall over India, while a negative IOD suppresses it.

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Q5 of 5

Why is the Indian monsoon often called the lifeline of the Indian economy?

Because it determines the schedule of industrial production cycles Because about 64% of Indians depend on agriculture, which itself depends on the southwest monsoon Because monsoon clouds reflect solar radiation and cool urban heat islands

About 64% of India's population depends on agriculture for livelihood, and agriculture in turn depends on adequate and timely monsoon rainfall. A good monsoon raises farm output, aids GDP growth, and drives rural consumption.

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Indian Express InfoGenIE

Question 1: What is the Monsoon in India?

The monsoon is a seasonal reversal of winds because of differential heating and the resulting pressure differences between land and sea. In summer, land surfaces heat more rapidly than adjacent seas, causing the air above the land to rise and generate a low-pressure area. This low pressure draws in cooler, moisture-laden air from high-pressure regions over the sea. It produces monsoon winds that bring widespread rainfall upon reaching land.

In winter, the process reverses, with winds blowing from the cooler land areas toward the sea, a phenomenon known as the retreating monsoon. This description provides a simplified overview of monsoon circulation.

Types of monsoon in India

There are two notable types of monsoon in India:

(1) Southwest monsoon: It occurs from June to September. It hits Kerala on the southwestern coast and then proceeds across the country. This monsoon is the primary monsoon affecting India, it not only brings respite from the heat but also contributes to the country’s ecosystem and economy, especially the growing of kharif crops. Over 70 per cent of the country receives the majority of its annual rainfall during the June to September season. The country’s Long Period Average is 880 mm.

(2) Northeast monsoon: It is another significant and persistent aspect of the Indian subcontinent’s climate system. Its name comes from the direction of the monsoon winds, which blow from northeast to southwest. It occurs from October to December and affects peninsular India. It is not as intense as the southwest monsoon but is crucial for the growth of rabi crops.

The northeast monsoon is key for Tamil Nadu, Kerala, Puducherry, Karaikal, coastal Andhra Pradesh, Rayalaseema and Yanam in southern India. Of the total annual rainfall, Tamil Nadu receives nearly 48 per cent (443.3mm) during the October to December months, important for rabi cultivation. The Northeast monsoon is also known as the winter monsoon, retreating monsoon, or reverse monsoon.

Question 2: What are the major factors that affect the Indian monsoon?

As several parts of India continue to reel under extreme heat, the United Nations’ weather agency has warned that a moderate or possibly strong El Niño could develop in the coming months, raising concerns over higher temperatures, erratic rainfall and stress on food and water systems. Against this backdrop, understanding the factors that influence the Indian monsoon becomes crucial.

The monsoon is affected by a complex interplay of atmospheric and oceanic phenomena, with major drivers including the El Niño-Southern Oscillation (ENSO), the Madden-Julian Oscillation (MJO), and the Indian Ocean Dipole (IOD), all of which can significantly affect the timing, intensity, and distribution of rainfall across the country.

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El Niño-Southern Oscillation

The El Niño Southern Oscillation is a climate phenomenon marked by changes in sea temperatures along the eastern Pacific Ocean, coupled with fluctuations in the overlying atmosphere. It can alter and interfere with the global atmospheric circulation, which, in turn, influences the weather worldwide. It has three phases: warm (El Niño, Spanish for little boy), cool (La Niña, Spanish for little girl), and neutral. It occurs in irregular cycles of 2 to 7 years.

In the neutral phase, the eastern side of the Pacific Ocean (near the northwestern coast of South America) is cooler than the western side (near the Philippines and Indonesia). This is due to the prevailing wind systems that move from east to west, sweeping the warmer surface waters towards the Indonesian coast. The relatively cooler waters from below come up to replace the displaced water.

During El Niño, the surface waters of this region of the Pacific get unusually warm, disrupting the flow of moist winds in India. The result is a weak or delayed monsoon for India, as well as dry spells in major agricultural states. There is also evidence that the frequency and severity of heatwaves India experiences are linked with the El Niño phenomenon.

The opposite happens when La Niña is underway: cooling of the surface waters of the eastern Pacific. India thus gets stronger, moisture-bearing winds, and typically experiences a boost in its southwest monsoon. In extreme situations, the excessive rain has caused flooding and crop damage as well.

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Inter-Tropical Convergence Zone (ITCZ)

The ITCZ is a dynamic region near the Equator where the trade winds of the northern and southern hemispheres come together. The intense sun and warm waters of the ocean heat up the air in this region and increase its moisture content. As the air rises, it cools, and releases the accumulated moisture, thus bringing rainfall. ITCZ plays an important role in the Indian monsoon.

During the monsoon season, this ITCZ is located over the Indian landmass. By September, as temperatures in the northern hemisphere begin to fall, the ITCZ starts moving southwards towards the Equator and further into the southern hemisphere, where the summer season begins to take shape.

Madden-Julian Oscillation (MJO)

MJO is one of the most important and complex ocean-atmospheric phenomena influencing Indian monsoons, with origins in the Indian Ocean. Notably, El Nino is a stationary system, whereas the MJO is a moving system of wind, cloud and pressure that brings rain as it circles around the equator.

A key feature of MJO is that a disturbance of clouds, wind and pressure moves eastward at a speed of 4-8 metres per second. Within 30 to 60 days, MJO wind bands can travel around the world and cause significant weather changes during their movement. In a favourable phase, it can enhance rainfall over India during the monsoon season.

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Indian Ocean Dipole (IOD)

IOD is the difference in sea surface temperatures (SSTs) between the eastern and western regions of the Indian Ocean. Like ENSO it also has three phases, positive, negative, and neutral. While a positive IOD leads to more rainfall, a negative phase results in less rainfall. A neutral IOD has minimal impact.

Question 3: Why is the Indian monsoon often called the lifeline of the Indian economy?

The Indian monsoon isn’t just an important geographical phenomenon; it holds great economic value as well. The monsoon is the axis around which revolves the entire agricultural cycle of India. It is because about 64 per cent of people in India depend on agriculture for their livelihoods, and agriculture itself is dependent on the southwest monsoon.

Monsoons & the Economic Life in India

Select a tab to explore each dimension of the monsoon's impact

Irrigation Gap Agri Dependency Monsoon–GDP Flood vs Drought Soil Erosion Crop Diversity Rabi & West. Dist. Year-Round Farming Rural Multiplier Monsoon & Culture

The Irrigation Gap

Irrigated farmland

55%

Rain-fed (monsoon-dependent)

45%

Only 55% of India's net sown area has irrigation coverage. The remaining 45% depends entirely on monsoon rainfall, making nearly half of all farmland highly vulnerable to erratic weather patterns.

Agricultural Dependency

64%

of Indians depend on agriculture for their livelihood

SW Monsoon

primary source of water for most farmland

With nearly two-thirds of India's population tied to farming, the success or failure of the southwest monsoon directly shapes livelihoods at a national scale.

Monsoon–GDP Link

📈

Boosts agricultural production

💹

Aids overall GDP growth

🌾

Drives up rural earnings

🛒

Raises rural consumption & demand

A good monsoon triggers a chain reaction — higher farm output leads to better GDP, stronger rural incomes, and increased consumer spending across India.

Flood vs Drought Dilemma

🌊

Excess rain → Floods, crop damage, displacement

🏜

Deficient rain → Droughts, failed harvests, income loss

Uneven or delayed monsoon pushes farmers into a no-win situation. Too much water causes flooding; too little triggers drought. Either way, crops and rural incomes bear the cost.

Soil Erosion Threat

⛈

Sudden intense rainfall strips fertile topsoil

🌱

Soil fertility declines season after season

Heavy, concentrated monsoon bursts wash away the fertile topsoil layer — quietly reducing the productivity of farmland over time and posing a long-term threat to India's agricultural base.

Crop Diversity Advantage

Varied regional rainfall patterns — from the heavy rains of the Northeast to the drier Deccan — enable an exceptionally wide range of crops across India.

Rice

Wheat

Pulses

Cotton

Sugarcane

Millets

Oilseeds

Spices

Different rainfall zones allow India to cultivate a diversity of crops that few countries can match — a direct product of the monsoon's geographic spread.

Rabi Crops & Western Disturbances

❄

Western disturbances deliver winter rains to north India

🌾

Wheat, mustard & other rabi crops benefit directly

While the southwest monsoon supports kharif crops, western disturbances play a parallel role in winter — delivering crucial rains for rabi cultivation in Punjab, Haryana, and Uttar Pradesh.

Year-Round Farming Potential

☀

Most of India stays warm enough for farming throughout the year

🏔

Exception: Himalayan region has cold winters that limit cultivation

Unlike temperate nations where winter halts farming, India's monsoon-shaped climate allows near-continuous cultivation across most of the country — a significant agricultural advantage.

Rural Economy Multiplier

🌧

Good monsoon → higher farm output

💰

Better income → more rural spending

🏪

Rural demand lifts local businesses

📊

Ripples into national economy

A strong monsoon sets off a multiplier effect — lifting consumer spending, local trade, and ultimately the broader national economy through rural India.

Monsoon Shapes Culture

The monsoon's influence extends well beyond agriculture, shaping everyday life across India's diverse regions.

🍛 Food Habits

👗 Clothing Styles

🏠 House Designs

🎶 Festivals & Art

Local rainfall patterns have shaped what people eat, what they wear, how homes are built — and the cultural traditions celebrated across India's monsoon-defined landscapes.

Agricultural prosperity in India depends very much on timely and adequately distributed rainfall. If it fails, agriculture is adversely affected, particularly in those regions where means of irrigation are not developed. A good monsoon raises agricultural production, aids GDP growth, and drives up rural earning and consumption. Thus, it has been called the lifeline of the Indian economy.

What is the Monsoon Mission?

Monsoon Mission is a national programme launched by the Ministry of Earth Sciences (MoES) with a vision to develop state-of-the-art dynamical prediction systems for the monsoon rainfall in different time scales.

Regional climatic variation in India is reflected in the vast variety of food, clothes and house types. Regional variations in monsoon climate help in growing various types of crops. Winter rainfall by temperate cyclones in north India is highly beneficial for rabi crops.

Post Read Questions

Prelims

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(1) The seasonal reversal of winds is the typical characteristic of (UPSC CSE, 2014)

(a) Equatorial climate

(b) Mediterranean climate

(c) Monsoon climate

(d) All of the above climates

(2) With reference to ‘Indian Ocean Dipole (IOD)’ sometimes mentioned in the news while forecasting Indian monsoon, which of the following statements is/are correct? (UPSC CSE, 2018)

1. IOD phenomenon is characterised by a difference in sea surface temperature between tropical Western Indian Ocean and tropical Eastern Pacific Ocean.

2. An IOD phenomenon can influence an EI Nino’s impact on the monsoon.

Select the correct answer using the code given below:

(a) 1 only

(b) 2 only

(c) Both 1 and 2

(d) Neither 1 nor 2

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(3) With reference to the Monsoons in India, consider the following statements:

1. The southwest monsoon brings more than half of India’s annual rainfall.

2. The ‘above normal’ rainfall is attributed mainly to the El Nino conditions.

3. During the northeast monsoon, the direction of the monsoon winds is from southwest to northeast.

How many of the statements given above are correct?

(a) Only one

(b) Only two

(c) All three

(d) None

(4) With reference to the Northeast monsoon, consider the following statements:

1. About 75 per cent of the country’s annual rainfall is received from the Northeast monsoon.

2. It is confined to the Southern peninsula with Tamil Nadu accounting for maximum rainfall.

3. It is also known as winter monsoon.

How many of the statements given above are correct?

(a) Only one

(b) Only two

(c) All three

(d) None

Mains

How far do you agree that the behavior of the Indian monsoon has been changing due to humanizing landscape? Discuss. (UPSC CSE 2015)

PRELIMS ANSWER KEY

1. (c)     2. (b)    3. (a)    4. (b)

(Sources: RBI Monthly Bulletin: Monsoon shortfall could weigh on growth, inflation outlook, What caused early national coverage by monsoon this year?, Monsoon out, monsoon in, NCERT)

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