Southwest Monsoon 2026: Why a 42% Rain Deficit Worries the RBI on Growth, Inflation

The core warning: The article, authored by RBI staff and published in the central bank's monthly bulletin, stated that an adverse south-west monsoon, if it materialises, "may weigh on the domestic growth-inflation outlook." Because nearly half of India's farmland depends directly on rain and food carries a large weight in the consumer price index, a poor monsoon is treated as a first-order risk to both output and prices.

The growth-inflation numbers: The RBI projected real GDP growth of 6.6% for 2026-27, noting the economy had still grown a strong 7.8% in Q4 of 2025-26 on the back of private consumption and fixed investment. CPI inflation for the year was pegged at 5.1%, with the bulletin observing that retail inflation rose to 3.9% in May from 3.5% in April on a broad-based increase across food, fuel and core items.

The global overlay: The article said the global landscape remains fragile despite an interim US–Iran peace agreement, warning that any breakdown could revive risks to energy prices, food security and growth. It is important to note that the views in a bulletin article are those of the authors and do not represent the official view of the RBI.

A seasonal reversal of winds: The monsoon is a seasonal reversal of wind direction with corresponding changes in rainfall. In summer, intense heating of the landmass over north-west India and the Tibetan Plateau creates a low-pressure zone, while the relatively cooler Indian Ocean stays at higher pressure. This pressure gradient pulls moisture-laden winds from sea to land, giving the south-west monsoon (June–September), which delivers about 75% of India's annual rainfall.

The ITCZ and the two branches: The northward shift of the Inter-Tropical Convergence Zone (ITCZ) over the Indian landmass draws in the monsoon current, which splits into the Arabian Sea branch and the Bay of Bengal branch. Orographic uplift along the Western Ghats and the north-eastern hills produces very heavy rain, while interior rain-shadow regions receive less.

The Long Period Average benchmark: The IMD measures performance against the Long Period Average (LPA) — the average season rainfall over a long base period. The current all-India south-west monsoon LPA (1971–2020) is 868.6 mm (about 87 cm). The seasonal forecast is classed as Normal (96–104% of LPA), Below Normal (90–96%), Above Normal (104–110%), Deficient (below 90%) and Excess (above 110%). The running cumulative departure of about –42% currently places the season firmly in the deficient range.

The ENSO cycle: El Niño and La Niña are the two extremes of the El Niño–Southern Oscillation (ENSO), driven by changes in sea-surface temperatures and air pressure over the equatorial Pacific. In an El Niño year, the central and eastern Pacific warms abnormally, trade winds weaken, and the zone of heavy rising air shifts eastward away from the Indian region — typically suppressing the Indian monsoon. La Niña, the cool phase, generally aids good rainfall in India.

The 2026 risk: The IMD has forecast below-normal seasonal rainfall at about 90% of LPA, with El Niño conditions expected to develop during the monsoon season. NOAA assessments suggest this El Niño could strengthen and persist into the 2026-27 winter, which is why the RBI explicitly flagged a likely deficient monsoon and potential El Niño as major domestic risks.

The Indian Ocean Dipole (IOD) modifier: The Indian Ocean Dipole — the difference in sea-surface temperatures between the western and eastern Indian Ocean — can soften or amplify the El Niño effect. A positive IOD usually supports Indian rainfall and can offset El Niño; for 2026, IOD conditions are broadly neutral, offering little counter-balance.

Through agriculture and rural demand: Agriculture supports nearly half of India's workforce and contributes close to a sixth of gross value added, yet about 51% of the net sown area is rain-fed and accounts for nearly 40% of food production. A delayed or deficient monsoon shrinks the kharif sowing window, lowers yields of rice, pulses, oilseeds and coarse cereals, and squeezes rural incomes and demand for tractors, two-wheelers and FMCG goods.

Through food inflation: Supply shortfalls in perishables and pulses push up food prices, which carry a large weight in the CPI basket. The RBI warned that retail inflation could rise towards the 6% upper tolerance band in the third quarter if weather-related pressures persist, complicating the inflation-targeting task.

Through the fiscal and external channels: Weak harvests can raise subsidy and import bills (for example, edible oils and pulses), while higher crude prices in a fragile geopolitical environment add imported inflation. This is why the monsoon is described as the single biggest annual variable for India's macroeconomic stability.

The pressure on the rupee: In April and May 2026, the rupee came under heavy pressure from rising crude prices, higher global bond yields and foreign portfolio outflows amid the US–Iran conflict, slumping to a record low of 96.96 per dollar. To arrest the fall, the RBI net sold $8.94 billion in the spot market in April, after a $9.76 billion net sale in March.

How sterilised intervention works: When the rupee weakens, the RBI sells dollars from its reserves and absorbs rupees, increasing dollar supply and curbing depreciation; in periods of strong inflows it buys dollars to build reserves. To prevent these operations from disturbing domestic money supply, the RBI conducts offsetting "sterilisation" operations. India's foreign exchange reserves fell to a more-than-one-year low of about $671.6 billion, reflecting this defence.

Capital-flow toolkit: Beyond spot sales, the RBI deployed structural measures to attract dollars — a swap facility for FCNR(B) (Foreign Currency Non-Resident Bank) deposits, expansion of the Fully Accessible Route (FAR) to longer-tenor government securities, and tax exemptions for foreign investors in government bonds. Aided by these measures, easing geopolitical tension and falling crude, the rupee recovered in June.

The MPC and the repo rate: The six-member Monetary Policy Committee, chaired by the RBI Governor, sets the repo rate (the rate at which the RBI lends to banks) to manage inflation and growth. On 5 June 2026 it unanimously kept the repo rate at 5.25% and retained a neutral stance, choosing to wait and watch amid weather and geopolitical uncertainty.

The inflation-targeting framework: Under the Flexible Inflation Targeting (FIT) framework, the RBI must keep CPI inflation at 4% within a band of +/- 2% (that is, 2% to 6%). A monsoon-driven food-price spike directly threatens this mandate, which is why the central bank watches rainfall distribution so closely.

The trade-off: Raising rates too early to pre-empt food inflation can choke growth that is already projected to slow; cutting too soon can entrench price pressures. The MPC therefore signalled a data-dependent approach, with its next meeting scheduled for early August.

Extreme spatial variability: The all-India deficit hides sharp regional contrasts. While large parts of central and western India stayed dry under heatwave conditions in early June, the north-east received exceptionally heavy rain. Mawsynram in Meghalaya — among the wettest places on Earth — recorded 526.5 mm in 24 hours, with RKM Sohra and Mawkyrwat also seeing extreme totals.

Why the hills are vulnerable: The Meghalaya plateau forces moist Bay of Bengal winds to rise (orographic effect), producing intense downpours. On steep, deforested or construction-disturbed slopes this triggers landslides — cutting off the strategic Shillong–Dawki tourist and trade route — while the Brahmaputra system causes annual flooding across Assam, affecting thousands in districts such as Dhemaji.

The disaster-management dimension: These events highlight India's disaster-preparedness needs — early-warning systems, slope stabilisation along highway projects, flood-plain management and relief logistics — coordinated through the National Disaster Management Authority (NDMA) and state disaster authorities under the Disaster Management Act, 2005.

Foodgrain buffers: As on 1 April 2026, rice stocks with the Food Corporation of India were nearly five times the buffer norm and wheat about three times, providing a strategic cushion for the Public Distribution System and against price spikes.

Water and irrigation: Reservoir storage, though it has slipped below last year's level, remains above the ten-year average; the share of irrigated area has risen over the past decade, reducing rain dependence for staples like rice and wheat.

Policy resilience: The RBI cited crop-diversification initiatives, water-conservation programmes and climate-resilient farming, alongside anchored inflation expectations, fiscal consolidation and adequate forex buffers, as sources of comfort that help India absorb a monsoon shock better than in the past.

Strengthen real-time monsoon and flash-flood early-warning systems, expanding Doppler radar and forecasting under initiatives like Mission Mausam, so distribution (not just seasonal totals) can be tracked.

Promote water-saving practices such as direct-seeded rice (DSR), micro-irrigation and watershed development to reduce the rain-fed sector's vulnerability.

Use foodgrain buffers proactively through open-market sales to contain food inflation, while protecting PDS and food-security commitments.

Invest in slope stabilisation, scientific road engineering and flood-plain zoning in landslide- and flood-prone regions like the north-east, coordinated under the NDMA framework.

Keep monetary policy data-dependent, balancing the inflation-targeting mandate against growth, while sustaining capital-flow measures and an adequate forex buffer to manage external volatility.