Current Affairs · · GS1 · Geography

India’s 2026 southwest monsoon ends with 12.6% rainfall deficit

India received 759.4 mm of rainfall during the 2026 southwest monsoon, 12.6% below normal and the lowest since 2015. Rainfall varied sharply across months and regions, and the India Meteorological Department expects below-normal all-India rainfall in October.

Event date:

REq1
  1. Context1 / 5
    • India recorded 759.4 mm of rainfall between June and September 2026, against a normal of 868.6 mm.
    • That is 87.4% of the Long Period Average (LPA), a seasonal shortfall of about 12.6%.
    • It was the lowest southwest monsoon rainfall since 2015, when India received 758.2 mm.
    • East and Northeast India received about 1,017.1 mm, the region's lowest monsoon rainfall since systematic records began in 1901.
    • The India Meteorological Department (IMD) has also forecast below-normal rainfall for the country in October 2026.
  2. Key highlights2 / 5

    A seasonal average can hide large differences between months and between regions.

    Month by month, the season measured up against the Long Period Average like this.

    • June — 65% of LPA. Large deficit.
    • July — 101% of LPA. Slightly above normal.
    • August — 84% of LPA. Deficient.
    • September — 92% of LPA. Below normal.

    The regional picture was uneven too.

    • East and Northeast India: about 25.6% below normal, the driest in the record since 1901.
    • South Peninsular India: about 24% below normal, among its weakest monsoons since 1901.
    • Central India: much closer to normal.
    • Odisha: the only meteorological subdivision with excess rainfall for the season.

    UPSC takeaway. Monsoon performance depends not just on the national total, but on where and when the rain falls.

  3. Note3 / 5

    Why the monsoon was deficient

    1. El Niño

    El Niño is the abnormal warming of the central and eastern equatorial Pacific Ocean. It can change atmospheric circulation and often weakens the Indian summer monsoon.

    Strong El Niño conditions developed during the 2026 season and were linked to the subdued rainfall.

    2. Low-pressure systems partly offset the deficit

    India still saw 14 low-pressure systems and 77 low-pressure-system days, against a normal of about 57 days.

    Such systems can carry moisture inland and produce concentrated spells of rain.

    3. Timing within the season

    June was exceptionally weak, July recovered, and rainfall weakened again through August and September.

    A simple analogy. Think of the monsoon as water delivered to a farm over four months. The final total matters, but crops also need the water at the right time.

  4. Key concepts4 / 5

    Long Period Average (LPA) is the average rainfall worked out over a long reference period. IMD uses it as the benchmark against which a season's rainfall is compared.

    For the June–September southwest monsoon, the all-India normal used for 2026 was about 868.6 mm.

    Why the LPA alone is not enough

    Suppose two regions each receive 900 mm during the season.

    • Region A gets rain steadily, through sowing and crop growth.
    • Region B gets most of it in a few intense downpours.

    Their seasonal totals look alike, but their farming and water outcomes can be very different.

    This is why questions on the monsoon usually turn on four things:

    • spatial distribution — where the rain falls;
    • temporal distribution — when it falls;
    • intensity — how much falls in a short period;
    • variability — how sharply rainfall changes between regions and periods.
  5. Note5 / 5

    Why the deficit matters

    Agriculture

    A weak or badly distributed monsoon can cut soil moisture, especially in rain-fed areas. That can affect crop growth and the moisture left in the ground before rabi sowing.

    Reservoirs and groundwater

    Rainfall refills rivers, reservoirs and aquifers. A deficit does not hit every basin equally, because distribution and the water already in storage both matter.

    Regional contrast

    A national deficit can sit alongside floods in particular regions. Odisha, for instance, had excess rainfall for the season despite the all-India shortfall.

    The October outlook

    IMD expects all-India rainfall in October to stay below normal, with above-normal temperatures likely over much of the country.

    For the October to December post-monsoon season, South Peninsular India is expected to get broadly normal rainfall, even though much of the country may stay below normal.

    The final takeaway. A monsoon should never be judged by the all-India seasonal total alone. Timing, location and intensity decide what it actually means for farming and for water.

Sources

Syllabus

PaperSubjectSub-topic
GS1GeographyImportant geophysical phenomena; the Indian monsoon and the factors affecting it
GS3EconomyAgriculture, water resources and climate-resilient planning
PrelimsGeographySouthwest monsoon, Long Period Average, El Niño and ENSO, low-pressure systems, regional rainfall variability

Topics

Agriculture GeographyClimatologyIndian GeographyOceanography

Related previous-year questions

Asked in earlier UPSC Prelims papers on this topic. Answer, then check.

  1. UPSC Prelims 2017 · Geography · Indian Geography

    With reference to ‘Indian Ocean Dipole (IOD)’ sometimes mentioned in the news while forecasting Indian monsoon, which of the following statements is/are correct? 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 El Niño’s impact on the monsoon. Select the correct answer using the code given below:

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

    Answer: B. VERDICT: The answer is 2 only. An Indian Ocean Dipole event can influence El Nino's impact on the monsoon, but the temperature difference is within the Indian Ocean, not between it and the Pacific. ANALYSIS: Statement 1 is INCORRECT. The Dipole is an irregular oscillation of sea surface temperatures in which the western Indian Ocean becomes alternately warmer and then cooler than the eastern part of the same ocean. The statement wrongly places the second pole in the tropical eastern Pacific. Statement 2 is CORRECT. A positive Dipole can bring good rainfall to India even in an El Nino year, while a negative one can aggravate the El Nino effect, so it modulates that influence. SOURCE: Indian Express explainer on the Indian Ocean Dipole and the monsoon. Source type EM. HOW TO CRACK IT: The name contains the disproof, since Indian Ocean Dipole means two poles within the Indian Ocean, and a pole located in the Pacific would make it a different phenomenon altogether. Reading a scientific term as a description of its own geography is the quickest route here. Keep the Dipole and El Nino distinct but linked, because the examinable point is that the two interact rather than that either alone determines the monsoon.

    Difficulty: hard · statement

    Open this question on its own page, with the full explanation →

Practice questions

  1. With reference to the Long Period Average (LPA) used by the India Meteorological Department, consider the following statements: 1. It provides a long-term benchmark against which a season’s rainfall can be compared. 2. A normal all-India seasonal rainfall necessarily means that every region received normal rainfall. 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
    Show answer

    Answer: A. Statement 1 is correct: the LPA is the average rainfall over a long reference period and serves as the benchmark for a season. Statement 2 is incorrect, because a national average can hide strong regional variation. In 2026 the all-India figure was 87.4% of the LPA, yet East and Northeast India were about 25.6% below normal while Odisha recorded excess rainfall.

    Difficulty: easy · statement

  2. Consider the following statements regarding El Niño: 1. It involves abnormal warming of the central and eastern equatorial Pacific Ocean. 2. It invariably causes drought throughout India. 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
    Show answer

    Answer: A. Statement 1 is correct. Statement 2 is incorrect: El Niño can weaken the Indian summer monsoon, but the effect is neither uniform across the country nor automatic. In 2026, strong El Niño conditions coincided with a 12.6% all-India deficit, yet Central India was close to normal and Odisha had excess rainfall.

    Difficulty: medium · statement

  3. Which of the following can influence the Indian southwest monsoon? 1. El Niño-Southern Oscillation 2. Indian Ocean Dipole 3. Madden-Julian Oscillation 4. Low-pressure systems over and around the Indian region. Select the correct answer using the code given below.

    1. 1 and 2 only
    2. 1, 2 and 3 only
    3. 1, 3 and 4 only
    4. 1, 2, 3 and 4
    Show answer

    Answer: D. All four can affect monsoon rainfall, at different scales of space and time. The El Niño-Southern Oscillation is the coupled ocean-atmosphere cycle in the Pacific that includes El Niño and La Niña. The Indian Ocean Dipole is the difference in sea-surface temperature between the western and eastern Indian Ocean. The Madden-Julian Oscillation is an eastward-moving band of cloud and rainfall that circles the tropics over weeks. Low-pressure systems carry moisture inland and deliver concentrated spells of rain.

    Difficulty: medium · statement

Mains practice

Answer-writing practice on this article. Attempt it first, then open the hints.

  1. GS1 · 150 words

    Explain why the amount of seasonal rainfall alone cannot adequately describe the performance of the Indian monsoon.

    Show hints
    1. Define the Long Period Average and state what a single seasonal percentage does and does not capture.
    2. Use the 2026 season to show variation within the months: a large June deficit, a near-normal July, then a weaker August and September.
    3. Show the spatial spread, with East and Northeast India and South Peninsular India far below normal while Odisha recorded excess rainfall.
    4. Bring in intensity and timing, explaining why rain that arrives outside the sowing and growth window is of less use to crops.
    5. Conclude that monsoon performance must be judged on distribution in space and time, not on the national total.
  2. GS3 · 250 words

    Examine how increasing spatial and temporal variability in monsoon rainfall can affect agriculture and water security in India.

    Show hints
    1. Explain what rising variability means in practice: heavier concentrated spells and longer dry gaps within the same seasonal total.
    2. Link this to rain-fed agriculture, soil moisture at sowing, and the moisture carried over into the rabi season.
    3. Set out the water side: uneven recharge of rivers, reservoirs and aquifers, and why basins differ depending on water already in storage.
    4. Point out that a national deficit can coexist with floods in particular regions, so planning cannot be driven by the all-India figure.
    5. Argue for responses such as crop and sowing advisories, storage and recharge works, and forecasts issued at a sub-regional scale.