Indian Climate and the Monsoon — Practice Questions
UPSC Prelims-pattern practice questions on the Indian monsoon with explanations — Indian Ocean Dipole, western disturbances, IMD dates, Köppen regions and ENSO.
Questions
These are original UPSC-pattern practice questions. Attempt each one before revealing the answer.
Consider the following statements about the Indian Ocean Dipole (IOD):
- In a positive IOD, sea surface temperatures in the western Indian Ocean are higher than in the eastern Indian Ocean.
- A positive IOD generally favours the Indian summer monsoon.
- The IOD is another name for El Niño.
Which of the statements given above are correct?
Solution
Statements 1 and 2 are correct — a positive IOD means a relatively warm western Indian Ocean, and it tends to support the Indian monsoon, sometimes offsetting El Niño. Statement 3 is wrong — the IOD is an Indian Ocean phenomenon; El Niño is a warming of the central and eastern equatorial Pacific. They are separate, though they interact.
Answer: B
Winter rainfall in Punjab and Haryana, which is beneficial for the rabi wheat crop, is mainly caused by
Solution
Western disturbances are low-pressure systems that originate over the Mediterranean region and are carried east by the westerly jet in winter, bringing rain and snow to north-west India. The retreating monsoon and Bay of Bengal cyclones mainly affect the east coast; the north-east winds give winter rain to Tamil Nadu.
Answer: A
According to the normal dates revised by the India Meteorological Department in 2020, by which date does the south-west monsoon normally cover the entire country?
Solution
IMD advanced the normal date for the monsoon covering the whole country from 15 July (the old date — the trap) to 8 July. 1 June is the normal onset date over Kerala.
Answer: C
In the Köppen scheme as applied to India, the “As” type of climate (monsoon with dry summer) is found along the
Solution
The Coromandel coast of Tamil Nadu gets most of its rain from October to December, so its summer is relatively dry — the “s” in As. The Konkan and Malabar coasts have heavy summer monsoon rain; western Rajasthan is hot desert (BWhw); the Ganga plain is Cwg (dry winter).
Answer: D
How many of the following are generally associated with a weaker Indian summer monsoon?
- El Niño
- Positive Indian Ocean Dipole
- La Niña
Solution
Only El Niño is generally associated with a weaker monsoon. A positive IOD and La Niña both tend to favour good rainfall. Remember that these are tendencies, not certainties.
Answer: A
Mains
Despite the expansion of irrigation, the Indian economy remains sensitive to the behaviour of the monsoon. Examine.
Solution
Introduction: The south-west monsoon delivers the bulk of India’s annual rainfall in four months. Its timing and distribution, not just its total, shape farm output and the wider economy.
Body:
- Agriculture: a large share of net sown area is still rain-fed; kharif crops such as pulses, coarse cereals, oilseeds and cotton depend on timely rain.
- Irrigation itself depends on the monsoon: reservoirs and groundwater are recharged by monsoon rain, so a weak season also weakens the following rabi crop.
- Prices: deficient or uneven rain pushes up food prices and affects monetary policy decisions.
- Rural demand: farm incomes drive demand for consumer goods, two-wheelers and fertilisers.
- Power and water: hydropower generation and urban water supply depend on reservoir levels.
- Variability and extremes: intra-seasonal breaks (such as the driest August since 1901 in 2023) and extreme rain events cause losses even in “normal” years.
Way forward: micro-irrigation, watershed development, crop diversification towards drought-hardy millets and pulses, better seasonal and extended-range forecasts, and crop insurance.
Conclusion: Irrigation has reduced, not removed, India’s monsoon dependence; resilience lies in water management and climate-smart agriculture.