Monsoon 2026 ends 12.6% below normal, India's weakest season since 2015
A dry June, a strong El Niño and a late rally: how did India end up with a 'deficient' monsoon?
Published 1 October 2026. Written by Pratidin from the reports linked at the end; every fact checked by a separate review before publishing. How we work
The India Meteorological Department (IMD) said on 30 September 2026 that the June to September southwest monsoon brought 759.4 mm of rain against a Long Period Average (LPA, the 1971 to 2020 average) of 868.6 mm. That is 87% of the LPA, a shortfall of 12.6%. It is the weakest season since 2015, the fourth lowest since 2001 and the 13th lowest since 1901. Under IMD's categories, anything below 90% of the LPA is 'deficient'. Rain was uneven across months: June gave 65% of its normal, July 101%, August 84% and September 92%.
The deficit was concentrated in the east and the south. East and Northeast India received 74% of their LPA, the lowest for that region since 1901. The South Peninsula got 542 mm, 76% of its LPA and its fourth lowest since 1901. Northwest India (94%) and Central India (97%) ended in the normal range. Of the 36 meteorological subdivisions, 18 (53% of the country's area) were normal, 17 (42%) were deficient and one, Odisha, was in excess. The monsoon reached Kerala on 4 June, three days late, covered the whole country on 9 July and began withdrawing from west Rajasthan on 19 September. The site covered that withdrawal; what is new is the final season verdict.
El Niño, the periodic warming of the central and eastern equatorial Pacific that tends to weaken the Indian monsoon, developed in June and strengthened through the season. IMD had forecast 92% of the LPA in April and lowered it to 90% (plus or minus 4%) in late May, so the outcome was close to, but below, its outlook. IMD's Director General said most parts of the country are expected to get below-normal rain in October to December, except some areas of northwest India and southern parts of peninsular India. The private forecaster Skymet described the season as ending in drought. The shortfall matters for rabi sowing, reservoir levels and food prices.
Prelims facts
- The 2026 southwest monsoon gave 759.4 mm against an LPA of 868.6 mm: 87% of the LPA, a 12.6% deficit, the weakest since 2015.
- IMD calls all-India seasonal rain below 90% of the LPA 'deficient'; 96% to 104% is 'normal'.
- East and Northeast India got 74% of their LPA, the region's lowest since 1901; the South Peninsula got 76%.
- Of 36 subdivisions, 18 were normal, 17 deficient and one (Odisha) in excess.
- El Niño developed in June and strengthened through the season; the last sub-90% monsoon, 2015, was also an El Niño year.
Quick recall
- 2026 southwest monsoon rainfall (June to September)
- 759.4 mm against an LPA of 868.6 mm: 87% of LPA, a 12.6% deficit.
- Base period of IMD's current Long Period Average
- 1971 to 2020 (about 87 cm for India as a whole).
- IMD band for all-India rain below 90% of LPA
- Deficient.
- Region with its lowest monsoon rainfall since 1901 in 2026
- East and Northeast India, at 74% of LPA.
- Only subdivision with excess rainfall in 2026
- Odisha.
- Monsoon onset over Kerala in 2026
- 4 June, three days after the normal date of 1 June.
- Last monsoon before 2026 to fall below 90% of LPA
- 2015, also an El Niño year.
- IMD's late-May 2026 forecast for the season
- 90% of LPA, with a model error of plus or minus 4%.
Prelims practice question
IMD classifies all-India southwest monsoon rainfall as 'deficient' when the seasonal total is:
- Less than 90% of the Long Period Average
- Between 90% and 95% of the Long Period Average
- Less than 96% of the Long Period Average
- Less than 80% of the Long Period Average
Show answer
Answer: (a) Less than 90% of the Long Period Average. IMD's categories are: deficient, below 90% of LPA; below normal, 90% to 95%; normal, 96% to 104%; above normal, 105% to 110%; excess, above 110%. The 2026 season, at 87%, is deficient.
Use this in UPSC Mains: previous-year questions
Recurring theme: Mechanism and variability of the Indian monsoon, El Niño and IOD, and drought preparedness
- How to use this
Use the deficient, El Niño-driven 2026 monsoon as a current case of an El Niño fallout and of the forecasting and contingency steps preparedness requires.
- The 2026 monsoon gave 87% of the LPA (a 12.6% deficit), the weakest since 2015; El Niño developed in June and strengthened, and 2015, the last sub-90% season, was also an El Niño year.
- Early warning: IMD forecast 92% of LPA in April, cut it to 90% (plus or minus 4%) in late May, and now expects below-normal October to December rain in most parts.
- Preparedness steps: contingency crop plans, timely seed for short-duration crops, drought assessment under the Manual for Drought Management, and micro-irrigation and watershed work before the next El Niño.
- How to use this
Use the 2026 data to show the monsoon's growing temporal and spatial unevenness, while noting that this season's deficit is attributed to El Niño, a natural driver.
- Monthly swings in 2026: June gave 65% of normal, July 101%, August 84% and September 92%.
- Spatial skew: East and Northeast India got 74% of LPA, the region's lowest since 1901, and the South Peninsula 76%, while Northwest (94%) and Central India (97%) were normal.
- Of 36 subdivisions, 17 (42% of area) were deficient and Odisha in excess; but the deficit came as El Niño strengthened through the season, so avoid attributing it wholly to landscape change.
The IOD node explains how a positive dipole can influence El Niño's impact on the monsoon, the core of this question.
Mains practice question
The 2026 southwest monsoon ended 12.6% below its Long Period Average amid a strengthening El Niño. Explain how El Niño influences the Indian monsoon and discuss the implications of a deficient monsoon for agriculture and the economy. (250 words)
Model answer
The 2026 southwest monsoon delivered 759.4 mm, 87% of the Long Period Average (LPA), its weakest since 2015, as El Niño strengthened through the season.
How El Niño affects the monsoon
- El Niño is the warming of the central and eastern equatorial Pacific. It weakens the Walker circulation and shifts rising air and rain-bearing convection eastward, away from the Indian region.
- Sinking air over the Indian Ocean and South Asia suppresses rainfall; many Indian droughts, including 2015, coincided with El Niño.
- A positive Indian Ocean Dipole can offset part of this effect.
The 2026 pattern
- June gave 65% of normal, July 101%, August 84%, September 92%.
- East and Northeast India received 74% of LPA, the lowest since 1901; the South Peninsula 76%.
- 17 of 36 subdivisions were deficient.
Implications
- Agriculture: rainfed kharif crops suffer; low soil moisture and reservoir storage threaten rabi sowing.
- Prices: lower output of pulses, oilseeds and vegetables can push up food inflation and complicate monetary policy.
- Rural economy: lower farm incomes reduce rural demand and raise the need for MGNREGS work and relief.
- Regional stress: IMD expects below-normal October to December rain in most regions.
Way forward
- Contingency crop plans and timely seed supply for short-duration crops.
- Drought assessment under the Manual for Drought Management and quick relief.
- Long-term: micro-irrigation, watershed development and climate-resilient varieties.
Resilience must be built before the next El Niño.
The basics
Why this matters
Much of India's farmland is rainfed, and the June to September southwest monsoon brings most of the country's annual rainfall. When IMD declares a season 'deficient', it is a signal for farm ministries, the RBI and disaster managers. In 2026 the season ended at 87% of normal.
What 'normal' means
IMD measures a season against the Long Period Average, the average of 1971 to 2020, about 87 cm for the whole country. It then sorts the season into bands. A number like '87%' only makes sense against these bands. See Long Period Average and IMD's rainfall categories.
- 1DeficientBelow 90% of LPA (2026 is here, at 87%)
- 2Below normal90% to 95% of LPA
- 3Normal96% to 104% of LPA
- 4Above normal105% to 110% of LPA
- 5ExcessAbove 110% of LPA
A season of uneven months
A seasonal total hides big swings. June 2026 was very weak, July was normal, August faltered and September partly recovered.
The ocean drivers
Two ocean patterns shape the monsoon. El Niño and the Indian monsoon: a warm eastern Pacific tends to pull rain-bearing convection away from India. Indian Ocean Dipole: a warmer western Indian Ocean (positive phase) tends to help Indian rain and can soften an El Niño. In 2026 El Niño developed in June and grew stronger through the season.
- Warming of the central and eastern equatorial Pacific
- Weakens the Walker circulation
- Usually reduces Indian monsoon rain
- Western Indian Ocean warmer than the eastern part
- Encourages convection over the Arabian Sea side
- Can partly offset El Niño's drying effect
What comes after September
Once the southwest monsoon retreats, Tamil Nadu, coastal Andhra Pradesh and nearby areas get much of their rain from the Northeast monsoon in October to December. IMD expects below-normal rain in most regions in that period, except some areas of northwest India and southern parts of peninsular India.
Go deeper
In one line: India's 2026 southwest monsoon closed at 87% of its Long Period Average, a 'deficient' season and the weakest since 2015, with the east, northeast and south hit hardest.
Why it matters for UPSC
Monsoon questions recur in GS1 geography (mechanism, El Niño, IOD) and GS3 (agriculture, food inflation, drought management). Prelims tests definitions such as the LPA and the forecast categories.
The core idea
IMD judges a season against the Long Period Average and IMD's rainfall categories. At 87%, 2026 falls in the 'deficient' band. The main climate driver was El Niño and the Indian monsoon, which developed in June and strengthened. The Indian Ocean Dipole is the other ocean pattern forecasters watch because it can offset El Niño. With the southwest monsoon gone, the south now looks to the Northeast monsoon, for which IMD expects below-normal rain in most regions.
Numbers and dates to remember
- 759.4 mm actual against 868.6 mm LPA: 87%, a 12.6% deficit.
- Monthly: June 65%, July 101%, August 84%, September 92% of normal.
- East and Northeast India 74% (lowest since 1901); South Peninsula 76%; Central 97%; Northwest 94%.
- 36 subdivisions: 18 normal, 17 deficient, 1 excess (Odisha).
- Onset over Kerala 4 June; full coverage 9 July; withdrawal began 19 September.
Where to go next
- Long Period Average and IMD's rainfall categories: what '87% of normal' actually means.
- El Niño and the Indian monsoon: the Pacific link behind most Indian droughts.
- Indian Ocean Dipole: the Indian Ocean pattern that can soften an El Niño.
- Northeast monsoon: the October to December rains that matter for Tamil Nadu.
Go deeper: was 2026 a forecasting success or a warning?
The case that IMD got it broadly right. IMD forecast 92% of the LPA in April and cut it to 90% plus or minus 4% in late May. The outcome, 87%, lies within that error band and in the below-normal territory IMD had signalled.
The case that regional forecasting still lags. Seasonal averages hide the pattern that matters for farmers. East and Northeast India had their weakest season since 1901 even as Central India ended in the normal range. Month-to-month swings, from 65% in June to 101% in July, make sowing decisions difficult.
El Niño years are not identical. El Niño and the Indian monsoon are linked, but the strength of the link varies. A positive Indian Ocean Dipole can soften the effect, as forecasters note in many seasons. In 2026 El Niño strengthened through the season, and the shortfall was the largest since 2015, the previous El Niño-driven deficient year.
What 'drought' means depends on who is speaking. IMD's term for the all-India season is 'deficient' under the Long Period Average and IMD's rainfall categories. The private forecaster Skymet described the season as ending in drought. For relief, states declare drought district by district using rainfall, crop and moisture indicators, which is a separate administrative process.
After September. The Northeast monsoon matters most for Tamil Nadu and nearby coastal areas. IMD's outlook of below-normal rain in most regions for October to December means stress may continue into the rabi season.
Long Period Average and IMD's rainfall categories
What '87% of normal' actually means.
In one line: The Long Period Average (LPA) is the average rainfall over a fixed base period, and IMD sorts each monsoon into five bands by comparing it with the LPA.
The benchmark
IMD's current LPA for the June to September season is based on 1971 to 2020 and is about 87 cm for India as a whole. In 2026 the exact all-India figure used was 868.6 mm. Regions, subdivisions and months each have their own LPA.
The five bands
- Deficient: below 90% of LPA.
- Below normal: 90% to 95%.
- Normal: 96% to 104%.
- Above normal: 105% to 110%.
- Excess: above 110%.
Why it is in the news
The 2026 season ended at 87% of the LPA, which places it in the deficient band. IMD's late-May forecast had put the chance of a deficient season at 60%.
Where to go next
El Niño and the Indian monsoon
The Pacific link behind most Indian droughts.
In one line: El Niño is a periodic warming of the central and eastern equatorial Pacific Ocean that usually weakens the Indian summer monsoon.
How it works
Normally, trade winds push warm water towards the western Pacific, and air rises over the warm Indo-Pacific region, feeding rain. This east-west loop is called the Walker circulation. During El Niño the trade winds weaken, warm water spreads east, and the zone of rising air shifts eastward. Over India, air tends to sink instead, which suppresses rainfall. The opposite phase, La Niña, usually helps the monsoon.
Why it is in the news
El Niño developed in June 2026 and strengthened through the season. The monsoon ended at 87% of normal, the weakest since 2015, which was also an El Niño year.
Where to go next
- Indian Ocean Dipole
- Long Period Average and IMD's rainfall categories
Indian Ocean Dipole
The Indian Ocean pattern that can soften an El Niño.
In one line: The Indian Ocean Dipole (IOD) is the difference in sea surface temperature between the western and eastern parts of the tropical Indian Ocean.
The two phases
In a positive IOD, the western Indian Ocean (near Africa) is warmer than the eastern part (near Indonesia). This tends to favour convection and rain over India. In a negative IOD the pattern reverses and tends to reduce Indian rain.
Why forecasters watch it
The IOD can modify El Niño's effect. A positive IOD can partly offset the drying effect of El Niño, which is why some El Niño years still see near-normal monsoons. UPSC asked about exactly this link in Prelims 2017.
Why it is in the news
With El Niño strengthening in 2026, forecasters tracked the IOD for any offsetting effect; the season still ended deficient.
Where to go next
Northeast monsoon
The October to December rains that matter for Tamil Nadu.
In one line: The northeast monsoon is the October to December rainy season, driven by winds from the northeast after the southwest monsoon retreats, and it is the main rain season for Tamil Nadu.
How it works
As the land cools after summer, the wind pattern reverses. Northeasterly winds cross the Bay of Bengal, pick up moisture, and bring rain to Tamil Nadu, Puducherry, coastal Andhra Pradesh, Rayalaseema, south interior Karnataka and Kerala. Low-pressure systems and cyclones from the Bay add to this rain.
Why it is in the news
After a deficient southwest monsoon, IMD said most parts of the country are likely to get below-normal rain in October to December, except some areas of northwest India and southern parts of peninsular India. This matters for rabi sowing and for reservoirs in the south.
Where to go next
- Long Period Average and IMD's rainfall categories
- Indian Ocean Dipole
Prelims-style quiz
Consider the following statements about the 2026 southwest monsoon:
1. All-India rainfall was 87% of the Long Period Average.
2. July was the only month in which rainfall was at or above its monthly normal.
3. Northwest India was the most deficient region of the country.
How many of the statements given above are correct?- Only one
- Only two
- All three
- None
Show answer
Answer: (b) Only two. 1 is correct: 759.4 mm against 868.6 mm is 87%. 2 is correct: July was 101% while June (65%), August (84%) and September (92%) were below normal. 3 is incorrect: Northwest India got 94% of LPA; East and Northeast India (74%) and the South Peninsula (76%) were the most deficient.
Consider the following statements:
Statement-I: The 2026 southwest monsoon is classified by IMD as a 'deficient' season.
Statement-II: IMD classifies all-India seasonal rainfall below 90% of the Long Period Average as deficient.
Which one of the following is correct in respect of the above statements?- Both Statement-I and Statement-II are correct and Statement-II explains Statement-I
- Both Statement-I and Statement-II are correct and Statement-II does not explain Statement-I
- Statement-I is correct but Statement-II is incorrect
- Statement-I is incorrect but Statement-II is correct
Show answer
Answer: (a) Both Statement-I and Statement-II are correct and Statement-II explains Statement-I. Both are correct. The season ended at 87% of LPA, and because IMD's 'deficient' band is below 90%, Statement-II explains Statement-I.
Consider the following pairs (2026 monsoon, region and share of LPA):
1. East and Northeast India : 74%
2. South Peninsula : 76%
3. Central India : 97%
4. Northwest India : 84%
How many of the pairs given above are correctly matched?- Only one
- Only two
- Only three
- All four
Show answer
Answer: (c) Only three. Pairs 1, 2 and 3 are correct as reported by IMD. Pair 4 is wrong: Northwest India received 94% of its LPA. 84% was the all-India figure for August.
Which one of the following best describes El Niño?
- A cooling of the western Indian Ocean relative to its eastern part
- A warming of the central and eastern equatorial Pacific Ocean
- A cold current along the coast of Somalia during the monsoon
- A strengthening of the trade winds across the equatorial Pacific
Show answer
Answer: (b) A warming of the central and eastern equatorial Pacific Ocean. El Niño is the periodic warming of the central and eastern equatorial Pacific, linked to weaker trade winds. The first option describes a negative Indian Ocean Dipole pattern; stronger trade winds are associated with La Niña.
With reference to the 2026 monsoon, consider the following statements:
1. The monsoon reached Kerala later than its normal onset date.
2. Of the 36 meteorological subdivisions, more were deficient than normal.
Which of the statements given above is/are correct?- 1 only
- 2 only
- Both 1 and 2
- Neither 1 nor 2
Show answer
Answer: (a) 1 only. 1 is correct: onset was on 4 June against a normal date of 1 June. 2 is incorrect: 18 subdivisions were normal, 17 deficient and one in excess.