Reuters reported on 24 August that two senior weather department sources expect India's June to September monsoon to finish about 15 percent below normal, which would be the weakest since 2009. That is a real and newsworthy figure. It is also not a number the India Meteorological Department has issued as a forecast, and it sits five points below IMD's last published seasonal point forecast. Here is what the department has actually put in writing, and the arithmetic a 15 percent season would require.
The number moving markets this morning is 15 percent. Reuters correspondent Rajendra Jadhav reported from Mumbai that two senior India Meteorological Department sources expect the country's southwest monsoon to end at 85 percent of normal, the lowest since 2009, and one of them said the September shortfall could be severe. The story named cotton, soybean, corn, pulses, wheat and rapeseed as exposed crops.
Nothing about that reporting is implausible. But there is a gap between the attributed figure and the published record, and the gap is worth stating precisely, because the two are being repeated interchangeably.
IMD issues a seasonal long range forecast in April, updates it at the end of May, and then issues monthly outlooks rather than revised seasonal totals. That means the department's most recent published number for the whole June to September season is now nearly three months old.
| Issued | Product | What it says |
|---|---|---|
| 13 Apr 2026 | Seasonal LRF | Jun to Sep rainfall 92% of LPA, model error ±5%, category below normal. LPA 87 cm, 1971 to 2020 base |
| 29 May 2026 | Updated seasonal LRF | Jun to Sep rainfall 90% of LPA, model error ±4%, category below normal |
| 30 Jun 2026 | July outlook | July below normal, under 94% of LPA. July LPA 280.4 mm |
| 31 Jul 2026 | Second half outlook | August below normal, under 94% of LPA (LPA 254.9 mm). Aug to Sep below normal, under 94% of LPA (LPA 422.8 mm) |
| 20 Aug 2026 | Extended range outlook | 1 Jun to 19 Aug rainfall at −13% of LPA. Below normal week 1 and week 2 |
| 24 Aug 2026 | Daily press release | Subdued rainfall likely to continue over peninsular India for the next week; isolated heavy to very heavy falls over Odisha, Jharkhand and Chhattisgarh |
One label needs disclosing before it confuses anyone. IMD classifies the running 13 percent deficit within its "normal" rainfall-distribution category, which spans departures from minus 19 to plus 19 percent. That monitoring category is separate from the narrower five-category system used in IMD's seasonal long range forecasts, where the 13 April release placed its 92 percent call in the "below normal" band. "Thirteen percent short" describes the arithmetic departure, not IMD's category label.
Note what is and is not in that list. IMD has published a below normal call for August, a below normal call for August plus September, and a running seasonal deficit of 13 percent. It has not published a revised seasonal total since 29 May, and its September outlook is not due until the end of this month. The 15 percent figure is a source-attributed expectation, not a departmental product.
The distance matters, and it needs stating carefully. IMD's 29 May release was a point forecast of 90 percent of the long period average with a stated model error of plus or minus 4 percentage points. An 85 percent outcome would fall one point below that model-error band. The band is not a formal confidence interval and does not rule out lower outcomes, but it does show that the Reuters sources are describing a materially drier finish than IMD's last published seasonal point forecast.
None of that makes the sources wrong, and none of it puts them outside the department. They are IMD people. Forecasters revise, someone inside IMD in late August knows things the May model did not, and IMD has since published below normal calls for August and for August plus September while the running deficit has grown. The point is narrower than a contradiction: the 15 percent figure has not been issued as a departmental product, and it should be read as a source-attributed expectation until it is.
The single national number hides the part that matters for crops. IMD's 20 August extended range outlook breaks the season to date into the four homogeneous regions:
| Region | 1 Jun to 19 Aug departure | Principal crops, general geography |
|---|---|---|
| Central India | −1% | Soybean, cotton, pulses (MP, Maharashtra, Gujarat) |
| Northwest India | −10% | Rice, cotton, and the rabi wheat belt |
| South Peninsula | −22% | Pulses, coarse cereals, reservoir-fed irrigation |
| East & Northeast India | −25% | Rice |
| All India | −13% |
The departure column is from IMD's 20 August document. The crop column is general cropping geography, is not part of that document, and is included only to locate the regions.
IAMElNino.com analysis: the geography does not line up neatly with the crop list in the coverage. Central India, which grows most of the country's soybean and a large share of its cotton, is currently the least deficient region in the country at 1 percent below normal. The two regions carrying the deep deficits are the South Peninsula and East and Northeast India, and the latter is the rice belt. The rainfall map places a larger current deficit over major rice-growing areas than over much of the central soybean and cotton belt. That does not by itself establish relative yield risk: sowing decisions, irrigation coverage, soil moisture, district-level rainfall distribution, timing within the crop cycle and the September finish all sit between a regional rainfall departure and a harvest.
Wheat and rapeseed belong in a different bucket entirely. Both are rabi crops, sown from around October onward. They are not damaged by a June to August deficit directly. Their exposure runs through what September does to soil moisture and reservoir recharge before the rabi sowing window opens. That is a real mechanism and it is why September carries double weight this year, but it is a chain of inference, and we have not verified current reservoir storage against a primary source for this piece.
This is the part the coverage leaves out, and it is checkable arithmetic rather than opinion. IMD publishes its monthly long period averages on the 1971 to 2020 base: June 165.4 mm, July 280.4 mm, August 254.9 mm, and an August plus September figure of 422.8 mm, which puts September at 167.9 mm. One note on the June figure: IMD's 29 May release, and the government press release carrying it, both print "165.4cm", an evident unit error, since 165.4 cm would exceed the entire seasonal total. 165.4 mm is the value consistent with IMD's seasonal and monthly climatology, and is what we use. Those four sum to 868.6 mm, which is exactly the seasonal LPA IMD states in its Monsoon 2024 report and matches the 87 cm quoted in its long range forecasts.
Applying the monthly departures Reuters reports, June at 35.4 percent below normal gives about 106.8 mm and July at a 1 percent surplus gives about 283.2 mm. June and July together therefore delivered roughly 87.5 percent of their combined normal, a deficit of 12.5 percent, which is consistent with the 13 percent IMD published through 19 August once a drier than normal partial August is added.
Now run it forward. An 85 percent season means 738.3 mm for the year. Subtract the 390 mm already banked in June and July and August plus September have to supply 348.3 mm against a combined normal of 422.8 mm. That is 82.4 percent of normal for the two months together.
| If August finishes at | September must deliver | September as % of its LPA |
|---|---|---|
| −15% (216.7 mm) | 131.6 mm | 78% (a 22% deficit) |
| −18% (209.0 mm) | 139.2 mm | 83% (a 17% deficit) |
| −20% (203.9 mm) | 144.3 mm | 86% (a 14% deficit) |
IAMElNino.com analysis: the 15 percent season is, arithmetically, a forecast about September. With August tracking near 15 percent below normal, an 85 percent season needs September to come in around 22 percent short. That is consistent with what the Reuters source said out loud, that the impact is likely to be severe in September with a double digit deficit, and it is the assumption the headline number is resting on. It is also the assumption IMD is about to publish a formal view on.
As a check on the method, applying 2009's published monthly percentages to these same long period averages reconstructs that season at 77.8 percent, against the 77 percent in IMD's 2009 end of season report. The residual is the shift in the LPA base between then and now, and it is small enough that the approach holds.
"Weakest since 2009" is a ranking claim, and the ranking belongs to Reuters rather than to us. Reuters reports that an 85 percent finish would be the weakest since 2009. Among the comparison years we checked against IMD's own end of season reports, 2015 came in at 86 percent of the long period average and 2014 at 88 percent. We have not verified every season from 2010 to 2025 against a primary source, so we are not asserting where the minimum of that period sits. What we can say is that an 85 percent finish would land one percentage point below 2015, the driest year in the set we checked.
One point is inside the noise of a seasonal expectation formed more than a month before the season ends. If 2026 lands at 86 percent it ties 2015 rather than falling below it. This is the sort of claim that should be checked against the final figure in early October, not settled in August.
It is also worth keeping 2009 in proportion. That season finished at 77 percent of the long period average, a 23 percent deficit, with June at 53 percent, July at 96 percent, August at 73 percent and September at 79 percent. 2026 so far is running ahead of 2009 in every single month: June at roughly 65 percent against 53, July at 101 percent against 96, and August so far near 85 percent against 73. An 85 percent season would still be roughly eight points less severe than 2009 itself, and 2009's figure sits on the LPA base in use at the time, so treat that gap as approximate rather than exact. Ranking and severity are different questions, and only one of them is in the headline.
El Nino is unambiguously present and strengthening. NOAA's Climate Prediction Center diagnostic discussion of 13 August 2026 keeps an El Nino Advisory in force and gives a greater than 90 percent chance of a very strong event during Northern Hemisphere autumn and winter 2026-27. IMD's own published outlooks name it: the 31 July release states that moderate El Nino conditions prevail and are expected to strengthen further during the monsoon season. So the Reuters sources are not inventing a link that the department disowns. The department wrote it down first.
What El Nino does not do is set the size of the deficit. Three El Nino-affected Indian monsoon seasons, all from IMD's own reports: 2009 finished at 77 percent of the long period average, 2015 at 86 percent, and 2023 at 94 percent. The three seasons produced very different rainfall deficits, which shows that El Nino presence alone does not determine the outcome. El Nino shifts the distribution of outcomes toward the dry side. It does not tell you which point in that distribution you land on, and any single-number impact forecast derived from event magnitude alone is doing something the physics does not support.
There is a second driver in play right now, and IMD is tracking it in the same document that carries the 13 percent figure. The 20 August extended range outlook places the Madden-Julian Oscillation in phase 6 with an amplitude above 1, moving toward phase 7 with weakening amplitude. Phases 6 and 7 put the MJO's convective envelope over the western Pacific, away from the Indian sector, and are associated with suppressed rainfall over India. A 2026 paper in Frontiers in Climate by Srinivasan and colleagues, with IMD Director General M. Mohapatra among the authors, found that prolonged residence in phases 6 and 7 carries a statistically significant negative correlation with all-India summer monsoon rainfall, r of −0.59 and −0.64 respectively, and argued that phase persistence rather than phase frequency is the more meaningful indicator. Two limits belong with that result. The authors present these as associations rather than direct causal links, and the analysis is restricted to La Nina years, using persistent active MJO residence defined by an amplitude of at least 1. The transferable point is narrower than it first appears: intraseasonal variability can materially modulate the seasonal ENSO background.
So the phase 6 signal is a plausible intraseasonal contributor to the current suppressed rainfall pattern, but this article cannot identify it as the trigger. The cited study examined persistent active MJO episodes during La Nina years, the present event is El Nino, and IMD expects the amplitude to weaken below 1 during week two, at which point the phase number carries much less meaning. What the evidence supports sits between the two readings in circulation: attributing the whole 13 percent to El Nino overstates it, and ignoring El Nino understates it. For the wider picture of how these signals combine, see our teleconnections dashboard and our earlier piece on what happens when the MJO goes quiet. The Indian Ocean Dipole, which has historically been the offset to El Nino's drying influence on India, was still neutral in IMD's 31 July assessment, with possible positive development by September. We covered that mechanism in The Other Ocean Is Watching.
None of this is a reason to dismiss the Reuters story. Two senior sources inside the forecasting agency saying the season is heading below the agency's published range is news, and Jadhav labelled the sourcing clearly. The failure mode is downstream, where an attributed expectation gets recycled as "IMD forecasts weakest monsoon since 2009" and a one point margin over 2015 becomes a settled fact. For the earlier stage of this same story, see our July report on India's June deficit, and for the crop side, why rice is the El Nino crop.