The India Meteorological Department issued its official forecast for the onset of the southwest monsoon over Kerala on May 15, 2026, predicting that the monsoon is likely to set in over Kerala on May 26, 2026, with a model error of ±4 days.
The normal onset date for the southwest monsoon over Kerala is June 1. A forecast of May 26 places the expected arrival eight days ahead of the climatological average — making 2026’s projected onset among the earliest in recent years if realised. The IMD’s six-predictor statistical model, which has been operational since 2005 and has produced accurate forecasts in 20 of 21 years between 2005 and 2025 — the sole exception being 2015 — gives the May 26 forecast a reasonably high degree of credibility. The model factors in minimum temperatures over north-west India, pre-monsoon rainfall over the south Peninsula, outgoing long wave radiation over the south China Sea and south-west Pacific, and lower tropospheric zonal wind patterns over the southeast and northeast Indian Ocean.
For context, the actual onset dates in recent years have been: June 1 in 2020, June 3 in 2021, May 29 in 2022, June 8 in 2023, May 30 in 2024, and May 24 in 2025 — with 2025 being the most recent early onset. The IMD’s forecasts for those same years were May 31, May 27, June 4, May 31, and May 27 respectively, indicating a consistent pattern of reasonable accuracy within the stated ±4 day margin.
An early monsoon onset carries significant economic weight, particularly in the current macro environment. India is navigating a cost-of-living shock driven by the West Asia crisis and Strait of Hormuz disruption — with April 2026 WPI at 8.3%, fuel and power inflation at 24.71% year on year, and the first fuel price hike in four years implemented on May 15. In this context, an early and robust monsoon has the potential to provide meaningful relief on the agricultural supply side: kharif sowing — covering paddy, pulses, oilseeds, and coarse cereals — typically begins after monsoon onset, and an early arrival gives farmers a longer effective growing season, improves soil moisture conditions, and reduces dependency on irrigation. The food index in April 2026 WPI stood at 2.31% — contained for now — and a good monsoon is the single most important variable keeping food inflation from joining the fuel-driven spike already visible in wholesale prices.
An early monsoon also supports rural demand revival, which has been under pressure from elevated input costs and fuel prices. Rural FMCG consumption, two-wheeler sales, and agricultural credit offtake all tend to track monsoon onset timing and distribution. For India’s central bank, a well-distributed and timely monsoon reduces one tail risk — food inflation — in a policy environment where crude-driven inflation is already narrowing the RBI’s room to manoeuvre.
The IMD will issue updated forecasts as the monsoon approaches. Actual onset will be declared when specified meteorological conditions — including sustained westerly winds, sustained rainfall over the Kerala coast, and outgoing long wave radiation thresholds — are met over at least five of 14 designated meteorological stations.
Disclaimer: This article is for informational purposes only and does not constitute investment advice. Please consult a SEBI-registered financial advisor before making investment decisions.