The southwest monsoon arrived in Kerala on June 4, 2026, marking a three-day delay from its normal schedule. While initial downpours triggered coastal orange alerts, the IMD has warned of a below-normal season at 90 percent of the long-period average due to a developing Pacific El Niño threat.
THIRUVANANTHAPURAM, India — The India Meteorological Department officially announced the onset of the southwest monsoon over Kerala on Thursday, June 4, 2026. The critical weather system, which brings roughly 80 percent of India’s total annual precipitation, crossed the coast after a three-day delay from its typical June 1 schedule.
While the arrival of heavy coastal downpours brings vital relief from intense summer heatwaves across the subcontinent, national climate scientists are advising caution. Simultaneous long-range indicators reveal that the critical four-month rain cycle is beginning under a strengthening El Niño threat. This brewing Pacific climate pattern has historically disrupted agricultural yields and driven food price inflation across south Asian economies.
Technical Onset Confirmed Amid Widespread Coastal Rain
According to an official press release issued by the India Meteorological Department (IMD), the definitive declaration followed two days of steady meteorological shifts across the Arabian Sea. The weather agency monitors specific criteria before declaring a formal onset. This includes sustained out-of-season rainfall exceeding 2.5 millimeters across 60 percent of designated tracking stations in Kerala, paired with deep westerly winds reaching speeds up to 40 kilometers per hour.
Following the initial landfall, the northern boundary of the monsoon advanced rapidly, covering the entire state of Kerala, the Union Territory of Lakshadweep, and neighboring Mahe. Specialized satellite imagery from the INSAT-3DS spacecraft confirmed massive convective cloud configurations moving northeastward. This system triggered immediate orange alerts and intense downpours across the low-lying coastal districts of Alappuzha, Kottayam, and Ernakulam.
El Niño Complications Cloud the Long-Range Forecast
Despite a strong initial push into southern parts of Karnataka and Tamil Nadu, the long-term outlook for the 2026 season remains subdued. In its updated seasonal forecast, the IMD revised its cumulative rainfall expectations downward to 90 percent of the Long Period Average (LPA). Based on historical data collected between 1971 and 2020, India’s national seasonal average stands at 868.6 millimeters for the June–September period.
Any final seasonal reading that falls below 90 percent of this average is officially categorized as a "deficient" monsoon. The IMD's current probabilistic modeling places the chance of a deficient or below-normal rainfall season at a high 60 percent.
The principal driver behind this dry forecast is the rapid transition of the El Niño-Southern Oscillation (ENSO). While Pacific sea-surface temperatures are currently holding in a neutral phase, tracking models from the National Oceanic and Atmospheric Administration (NOAA) indicate an 82 percent chance of a moderate-to-strong El Niño pattern developing between June and August 2026.
Core Monsoon Performance and Regional Projections
The initial regional distribution updates highlight significant variations in projected rainfall across the country:
| Geographical Performance Matrix | Projected Seasonal Volume Status | Historical Context (1971–2020 Baseline) |
| National Cumulative Outlook | Below Normal (90% of LPA) | National Base Median: 868.6 mm |
| Northeast Homogeneous Region | Normal (96% to 104% of LPA) | Steady Himalayan moisture feed |
| Central & Northwest Belts | Deficient / High Risk of Spells | Major dependency for rain-fed crops |
| South Peninsular Region | Below Normal (Improves late June) | Initial technical delay of 3 days |
Data source: India Meteorological Department Seasonal Forecast Center.
Official Sources Section
The technical data, regional alerts, satellite observations, and long-range seasonal averages used in this report are sourced directly from weather status charts compiled by the India Meteorological Department (IMD) and official climate briefings distributed by the Ministry of Earth Sciences.
Quote Section
"According to officials from the agricultural ministry, India's state-managed buffer stock of 43 lakh tonnes of pulses will serve as an essential economic cushion if erratic spatial distribution disrupts primary summer sowing windows."
Why It Matters
For rural farmers, commodities investors, corporate food processors, and everyday consumers, the progress of the southwest monsoon is a major economic driver. Nearly half of India's net cultivated farmland lacks permanent irrigation networks, relying entirely on these summer rains to sustain critical summer crops like paddy rice, pulses, soybeans, and sugarcane. If the emerging El Niño pattern severely cuts rainfall across central and western agricultural belts, it could lead to lower crop yields and higher retail food prices, testing rural incomes and complicating monetary policy decisions into 2027.
Key Facts at a Glance
Landfall Declared: The IMD confirmed the formal onset of the southwest monsoon over Kerala on June 4, 2026, tracking three days behind schedule.
Deficit Alert: Seasonal rainfall is projected to wrap up at a below-normal 90 percent of the country's Long Period Average (LPA).
Pacific Headwinds: International climate agencies report an 82 percent chance of a dry El Niño phenomenon intensifying during the mid-monsoon phase.
Immediate Alerts: Heavy opening rains prompted immediate localized orange alerts across multiple districts in Kerala and Tamil Nadu.
Buffer Shield: The Indian government has built up a record 43 lakh tonne pulse reserve to help stabilize local food prices against crop shortfalls.
FAQ Section
Q1: What structural benchmarks does the IMD use to declare the official monsoon onset?
The onset is declared only when 60 percent of the 14 regulated weather stations across Kerala and Lakshadweep record a minimum of 2.5 mm of rainfall for two consecutive days, accompanied by deep westerly wind fields and specific outgoing longwave radiation values.
Q2: What exactly is the Long Period Average (LPA) used in rain forecasts?
The LPA is the benchmark baseline calculated by averaging actual rainfall over a 50-year period. India's current nationwide benchmark is 868.6 mm, which is used to classify whether a season is normal, excess, or deficient.
Q3: How does the El Niño phenomenon alter India's summer rainfall?
El Niño involves the anomalous warming of surface waters in the central and eastern Pacific Ocean. This shift alters global atmospheric circulation patterns, frequently weakening the moisture-laden trade winds that fuel India’s monsoon system.
Source: Official press bulletins published by the India Meteorological Department (IMD); agricultural buffer registries maintained by the Ministry of Consumer Affairs; and global sea-surface data issued by NOAA.
