Southwest monsoon ends with 12% deficit

Geography · 1 October 2026 · Based on The Hindu (original report)

2-minute summary

India's 2026 southwest monsoon concluded with a significant 12.6% rainfall deficit, recording 759.4 mm of rain against the normal 868.6 mm. Operating at just 87% of the Long Period Average (LPA), this marks the driest monsoon season for the country since 2015. The deficit was primarily driven by one of the strongest El Niño events in recent history, which suppressed rainfall across major regions. Notably, East and Northeast India experienced their driest monsoon since systematic record-keeping began in 1901, with a 25.6% deficit. The Southern Peninsula also recorded its fourth-driest monsoon since 1901, with a 24.3% deficit. Out of 36 meteorological subdivisions, 17 were classified as rain-deficient. The India Meteorological Department (IMD) expects a hotter and drier October across most parts of the country as the monsoon withdraws, though increased western disturbances under El Niño conditions may bring some winter crop-assisting soil moisture to parts of northwest India.

Why it's in the news

The India Meteorological Department (IMD) released the final cumulative rainfall data for the 2026 southwest monsoon season, confirming a 12.6% national deficit and highlighting severe regional droughts in East, Northeast, and Southern India.

Facts to remember

• India's 2026 southwest monsoon ended with 759.4 mm of rain, which is 12.6% below the normal benchmark of 868.6 mm.
• At 87% of the Long Period Average (LPA), the 2026 monsoon is the lowest recorded since 2015 (which stood at 758.2 mm).
• The East and Northeast region recorded 1,017.1 mm of rainfall, making it the driest monsoon for the region since 1901.
• The Southern Peninsula recorded 542 mm of rain, marking its fourth-lowest monsoon rainfall since 1901.
• Out of 36 meteorological subdivisions in India, 17 (covering 42% of the country's land area) experienced deficient rainfall during the 2026 season.

Background and context

The Southwest Monsoon (June to September) is the primary source of water for India, accounting for over 70% of the country's annual rainfall and driving the kharif crop cycle. The India Meteorological Department (IMD) measures monsoon performance against the Long Period Average (LPA), which is currently calculated using the 50-year average rainfall from 1971 to 2020 (868.6 mm). A key driver of monsoon variability is the El Niño-Southern Oscillation (ENSO). El Niño, characterized by the warming of sea surface temperatures in the central and eastern tropical Pacific Ocean, historically correlates with suppressed monsoon rainfall over India. Conversely, La Niña typically brings above-normal rainfall. The 2026 deficit highlights the growing vulnerability of Indian agriculture to global climate anomalies, despite advancements in IMD's long-range forecasting models.

Committees and reports

• Ashok Dalwai Committee on Doubling Farmers' Income — Emphasized the need for climate-resilient agriculture, micro-irrigation, and drought-proofing strategies to mitigate the impact of deficient monsoons on rural incomes.

Government schemes

• Pradhan Mantri Fasal Bima Yojana (PMFBY) — Provides financial support and insurance cover to farmers suffering crop loss due to natural calamities like drought.
• Pradhan Mantri Krishi Sinchayee Yojana (PMKSY) — Aims to expand cultivable area under assured irrigation ('Har Khet Ko Pani') and improve water-use efficiency ('More Crop Per Drop') to reduce monsoon dependence.

International organisations

• World Meteorological Organization (WMO) — The UN specialized agency that monitors global climate drivers, including El Niño and La Niña, which directly influence the Indian monsoon.

Previous UPSC questions on this theme

• Prelims GS-1 2026 — With reference to the climate of Andaman and Nicobar Islands, which of the following statements is/are correct ? 1. The climate can be defined as a humid, tropical coastal climate. 2. It receives rainfall from both South-west monsoon and North-east monsoon. 3. Maximum precipitation is between December and May. Select the answer using the code given below : (a) 1 only (b) 1 and 2 (c) 2 and 3 (d) 3 only
• Prelims GS-1 2020 — With reference to Ocean Mean Temperature (OMT), which of the following statements is/are correct ? 1. OMT is measured up to a depth of 26°C isotherm which is 129 meters in the south-western Indian Ocean during January – March. 2. OMT collected during January – March can be used in assessing whether the amount of rainfall in monsoon will be less or more than a certain long-term mean. 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

Mains practice: Explain the mechanism of the Southwest Monsoon and discuss how global atmospheric-oceanic phenomena like El Niño influence its spatial and temporal distribution over India.

The Southwest Monsoon (June–September) is driven by the differential heating of the landmass of South Asia and the adjacent Indian Ocean, creating a low-pressure zone over the Tibetan Plateau that draws moisture-laden winds from the high-pressure zone in the southern Indian Ocean.

Global atmospheric-oceanic phenomena, particularly the El Niño-Southern Oscillation (ENSO), significantly influence this system:

• **El Niño Mechanism**: Characterized by the anomalous warming of sea surface temperatures (SSTs) in the central and eastern tropical Pacific Ocean. This shifts the convective Walker Circulation eastward, weakening the trade winds and suppressing the ascending motion of air over the Indian subcontinent, which leads to deficient rainfall.

• **Spatial Variability**: During El Niño years, certain regions face extreme deficits. For instance, in 2026, East and Northeast India recorded their driest monsoon since 1901 (25.6% deficit), and the Southern Peninsula faced its fourth-driest season. Conversely, western disturbances can sometimes cause localized excess rain in the northwest.

• **Temporal Variability**: El Niño can delay the onset of the monsoon, cause prolonged dry spells (break monsoons) in July and August, and accelerate early withdrawal, as seen in the 2026 season where August and September faced highly erratic distributions.

• **Indian Ocean Dipole (IOD) Interaction**: A positive IOD (warmer western Indian Ocean) can sometimes counteract the negative impacts of El Niño, whereas a negative IOD exacerbates the drought conditions.

To mitigate these climate-induced vulnerabilities, India must transition from supply-side water management to demand-side efficiency, promote climate-resilient crop varieties, and strengthen localized agro-meteorological forecasting.

Prelims practice questions

Q1. With reference to the Long Period Average (LPA) of rainfall in India, consider the following statements: 1. The current LPA for the southwest monsoon is calculated based on the 50-year average rainfall from 1971 to 2020. 2. A monsoon is officially classified as 'deficient' by the India Meteorological Department (IMD) if the actual seasonal rainfall is less than 90% of the LPA. Which of the statements given above is/are correct?

1. 1 only
2. 2 only
3. Both 1 and 2
4. Neither 1 nor 2

Answer: C. Both statements are correct. The IMD updated the LPA to 868.6 mm based on the 1971-2020 data. A monsoon is classified as 'deficient' when the rainfall is less than 90% of the LPA.

Q2. How does a strong El Niño event typically impact the Indian subcontinent's weather patterns?

1. It weakens the monsoon winds, leading to deficient rainfall and warmer-than-normal winter temperatures.
2. It causes severe cooling of the landmass, leading to prolonged winter cold waves.
3. It has no correlation with the southwest monsoon but increases northeast monsoon rainfall.
4. It strengthens the trade winds, leading to excess monsoon rainfall.

Answer: A. El Niño is associated with the warming of the Pacific Ocean, which weakens the Walker Circulation and the Indian monsoon winds, leading to deficient rainfall. It is also associated with warmer winter temperatures in India.

Q3. According to the India Meteorological Department (IMD) data for the 2026 southwest monsoon, which of the following regions recorded its driest monsoon since systematic record-keeping began in 1901?

1. Southern Peninsula
2. East and Northeast India
3. Central India
4. Northwest India

Answer: B. As per the IMD, the East and Northeast region recorded 1,017.1 mm of rainfall, making it the driest monsoon for that region since systematic records began in 1901.

Revision flashcards

• What is the current Long Period Average (LPA) value for the Southwest Monsoon in India (as of October 2026)? 868.6 mm, calculated based on the 50-year average from 1971 to 2020.
• What percentage of the LPA did the 2026 Southwest Monsoon record, and when was it last this low? 87% of the LPA (759.4 mm), which is the lowest recorded since 2015.
• How does the IMD define a 'deficient' monsoon subdivision? When the rainfall deficit in that subdivision is 20% or more below the normal LPA.
• What is the primary global oceanic phenomenon that suppressed the 2026 Indian monsoon? A strong El Niño event (warming of the central and eastern tropical Pacific Ocean).
• Which Indian region experienced its driest monsoon since 1901 during the 2026 season? The East and Northeast region, which faced a 25.6% rainfall deficit.