🗞️ Why in News The India Meteorological Department, in its monthly outlook issued on July 31, 2026, forecast August 2026 rainfall at below 94 per cent of the Long Period Average and flagged the entire second half of the monsoon season, August and September, as likely to be below normal.
The Forecast
| Parameter | Detail |
|---|---|
| Issuing body | India Meteorological Department (IMD) |
| Issued | 31 July 2026 |
| August 2026 forecast | Below 94 per cent of the Long Period Average (LPA) |
| Second half of season (Aug-Sep) | Below normal |
| Regional exceptions | Parts of peninsular, central, eastern and northeastern India, and parts of northwest India, may still see normal to above-normal rainfall |
| Attributed driver | Moderate El Nino conditions, expected to strengthen |
| Indian Ocean Dipole | Currently neutral; some international forecasting centres expect it to turn positive in September |
Reading IMD’s Categories Correctly
IMD’s seasonal rainfall classification is a specific, defined scale that UPSC tests directly, and “below 94 per cent of LPA” is not a casual phrase.
| Category | Range (as percentage of LPA) |
|---|---|
| Deficient | Less than 90 per cent |
| Below normal | 90 to 96 per cent |
| Normal | 96 to 104 per cent |
| Above normal | 104 to 110 per cent |
| Excess | More than 110 per cent |
The Long Period Average (LPA) is the average rainfall recorded over a long reference period, used as the benchmark against which any season’s performance is measured.
Why August Specifically Is the Worst Month for This
A rainfall deficit is not equally damaging in every month of the monsoon. June rainfall drives sowing; a June deficit delays planting but can often be recovered if later rain arrives. August rainfall drives grain filling, the stage at which the kharif crop’s yield per plant is actually determined, and a deficit here cannot be recovered by later rain because the biological window has closed.
| Monsoon month | Agricultural function | Consequence of deficit |
|---|---|---|
| June | Sowing and transplanting | Delayed planting; partially recoverable |
| July | Vegetative growth | Stress, but some resilience |
| August | Grain filling, yield determination | Yield loss largely irrecoverable |
| September | Crop maturation; reservoir topping-up for rabi | Affects rabi water availability more than kharif yield |
August is also the peak reservoir-recharge month. A deficit therefore hits twice: it reduces the current kharif yield and it lowers the reservoir storage baseline that the following rabi season’s irrigation depends on.
The Transmission Chain to Watch
| Stage | Mechanism |
|---|---|
| Rainfall deficit in August | Kharif yield falls, particularly for rain-fed crops (pulses, coarse cereals, oilseeds) |
| Lower reservoir storage | Reduced irrigation water for the rabi sowing season that follows |
| Reduced supply | Upward pressure on food prices, particularly pulses and vegetables |
| Food inflation | Feeds into headline CPI, in which food carries a substantial weight |
| Monetary policy | Constrains the RBI’s room to ease rates, since food-driven inflation complicates the inflation-targeting framework |
| Rural demand | Lower farm incomes reduce rural consumption, with knock-on effects for the wider economy |
The El Nino and IOD Interaction
IMD attributes the outlook to prevailing El Nino conditions. The important analytical nuance, and one UPSC frequently tests, is that El Nino’s effect on the Indian monsoon is probabilistic, not deterministic, and is significantly modulated by the Indian Ocean Dipole (IOD).
A positive IOD (warmer western Indian Ocean relative to the east) tends to enhance Indian monsoon rainfall and can partially offset El Nino’s suppressing effect. IMD’s note that the IOD is currently neutral, with some international forecasting centres expecting it to turn positive only in September, is therefore consequential: the offsetting factor arrives after the month in which the deficit does the most agricultural damage.
UPSC Relevance
GS Paper 1: Important geophysical phenomena, climatology; monsoon mechanism and variability.
GS Paper 3: Agriculture, cropping patterns, irrigation; food security; disaster management.
Prelims pointers:
- August 2026 forecast: below 94 per cent of LPA; IMD’s “below normal” category is 90-96 per cent of LPA.
- LPA (Long Period Average): the long-run reference average against which seasonal rainfall is measured.
- Attributed driver: moderate El Nino conditions, expected to strengthen; Indian Ocean Dipole currently neutral, with some international centres expecting a positive IOD in September.
- A positive IOD tends to enhance Indian monsoon rainfall and can partially offset El Nino.
Mains question: “The agricultural consequence of a monsoon deficit depends more on when it occurs than on how large it is.” Examine this claim with reference to IMD’s below-normal August 2026 forecast and the kharif crop cycle. (250 words)
📌 Facts Corner, Knowledgepedia
The forecast:
- IMD outlook issued 31 July 2026: August rainfall below 94 per cent of LPA; Aug-Sep below normal.
- Exceptions: parts of peninsular, central, eastern and northeastern India, and parts of northwest India.
IMD rainfall categories (as % of LPA):
- Deficient <90; Below normal 90-96; Normal 96-104; Above normal 104-110; Excess >110.
Why August matters most:
- August is the kharif grain-filling stage, when yield is determined; deficits here are largely irrecoverable.
- August is also the peak reservoir-recharge month, so a deficit also reduces rabi irrigation availability.
Drivers: moderate El Nino conditions, expected to strengthen; IOD neutral now, with some international centres expecting it to turn positive in September, meaning the offsetting factor arrives late.
Sources: India Meteorological Department, Ministry of Earth Sciences, The Hindu
Source: The Wrong Month to Be Dry: IMD Forecasts a Below-Normal August — Ujiyari.com | Free UPSC & State PCS Current Affairs
