Weak September rains could push FY27 inflation to 5.5% or higher: Report
A banking-sector research report projects that FY27 (2026-27) consumer price inflation could rise to 5.5% or higher if September rainfall remains weak, potentially amid El Nino conditions
As of late August 2026, the southwest monsoon was running roughly 13% below the Long Period Average (LPA), with sharply uneven regional distribution — the southern region around 22% below normal, the eastern/north-eastern region around 27% below normal, and states such as Andhra Pradesh and Bihar recording deficits of about 40% and 42% respectively
Kharif sowing has recovered sharply from an earlier deficit — from about 16% below last year's level in mid-July to only about 1.5% below last year's level by late August
Reservoir storage offers some cushion (about 64% of live capacity as of late August) but remains roughly 18% below year-ago levels, and the inflationary impact of a weak monsoon is expected to show up gradually through rural demand and food prices
Flexible Inflation Targeting (FIT) Framework and the RBI's Monetary Policy Committee
India's monetary policy operates under a Flexible Inflation Targeting framework, introduced through a 2016 amendment to Section 45ZA of the Reserve Bank of India Act, 1934 (via the Finance Act, 2016). Under this provision, the Central Government, in consultation with the RBI, notifies a numerical inflation target once every five years, based on the headline Consumer Price Index (CPI). The six-member Monetary Policy Committee (MPC), constituted under Section 45ZB of the RBI Act, sets the policy repo rate to keep inflation within this band.
Key Details
- Inflation target: 4% CPI inflation, with a tolerance band of +/-2% (i.e., 2%-6%)
- Legal basis: Section 45ZA (target-setting) and Section 45ZB (MPC composition) of the RBI Act, 1934, inserted by the Finance Act, 2016
- MPC composition: 6 members — 3 from RBI (Governor as Chair, a Deputy Governor, one RBI official) and 3 external members appointed by the Government
- The inflation target was retained at 4% (+/-2%) for the 2026-2031 period, continuing the framework first set for 2016-2021 and renewed for 2021-2026
A monsoon-driven inflation spike toward 5.5% would sit above the RBI's upper tolerance threshold of 6% only if it worsens further, but it would still pressure the MPC's ability to keep headline inflation anchored near the 4% target, potentially constraining future rate cuts.
Consumer Price Index (CPI) — Compilation and the New 2024 Base Year
The CPI, India's principal inflation gauge, is compiled monthly by the National Statistical Office (NSO) under the Ministry of Statistics and Programme Implementation (MoSPI). India shifted its CPI base year from 2012 to 2024 (2024=100), based on the Household Consumption Expenditure Survey (HCES) 2023-24, adopting the UN's COICOP 2018 classification.
Key Details
- Compiling body: NSO/MoSPI; released monthly
- Old base year: 2012; new base year: 2024=100 (based on HCES 2023-24)
- Weight revision: food & beverages weight fell from about 45.86% (2012 series) to about 36.75% (2024 series), reflecting changed consumption patterns
- Number of items in the basket increased from 299 to 358 at the all-India level under the new series
Because food and beverages still carry the largest single weight in CPI (~37%), a monsoon-driven spike in food prices has an outsized effect on headline CPI inflation, which is the transmission channel the report is flagging for FY27.
Southwest Monsoon and the Long Period Average (LPA)
The India Meteorological Department (IMD) measures monsoon performance against the Long Period Average — the average rainfall recorded over a fixed 50-year reference period — with "normal" defined as 96-104% of LPA. The southwest monsoon (June-September) delivers roughly 70-75% of India's annual rainfall and is the primary determinant of kharif crop output, reservoir replenishment, and rural income.
Key Details
- LPA-based classification: Deficient (<90% of LPA), Below Normal (90-96%), Normal (96-104%), Above Normal (104-110%), Excess (>110%)
- September is typically the withdrawal phase of the monsoon but still contributes meaningfully to kharif crop maturation and reservoir filling
- El Nino (warming of central/east Pacific sea surface temperatures) is historically associated with weaker Indian monsoons, though the correlation is probabilistic, not deterministic
The report's central claim — that September rainfall performance will determine whether FY27 inflation stays contained or rises to 5.5%+ — reflects the monsoon's outsized role in food-price formation through kharif output and rural demand.
Reservoir Storage and the Central Water Commission
The Central Water Commission (CWC), under the Ministry of Jal Shakti, monitors live storage in 176 major reservoirs across India on a weekly basis, providing an early indicator of water availability for irrigation, drinking water, and hydropower through the dry season.
Key Details
- CWC tracks 176 reservoirs nationally for live storage capacity
- As of late August 2026, storage stood at about 64% of live capacity, roughly 18% below the year-ago level
- Reservoir levels act as a buffer against monsoon shortfalls for rabi-season irrigation, cushioning food output even if kharif is affected
The report cites below-normal reservoir levels as a factor reducing the cushion available to offset a weak September monsoon, reinforcing the inflation risk.
- Projected FY27 CPI inflation if September rains stay weak: 5.5% or higher
- RBI's inflation target: 4% CPI, tolerance band 2%-6% (retained for 2026-2031)
- Southwest monsoon deficit (as of late August 2026): ~13% below LPA
- Regional deficits: southern region ~22% below normal, eastern/north-eastern ~27% below normal; Andhra Pradesh ~40%, Bihar ~42% deficit
- Kharif sowing deficit narrowed from ~16% (mid-July) to ~1.5% below last year's level (late August)
- Reservoir storage: ~64% of live capacity across 176 CWC-monitored reservoirs, ~18% below last year
- CPI base year revised from 2012 to 2024 (HCES 2023-24 based); food & beverages weight fell from ~45.86% to ~36.75%