What has the IMD announced ahead of this year’s monsoon? | Explained
The India Meteorological Department (IMD) has issued its Long Range Forecast (LRF) for the 2026 Southwest Monsoon season (June–September), predicting below-n...
What Happened
- The India Meteorological Department (IMD) has issued its Long Range Forecast (LRF) for the 2026 Southwest Monsoon season (June–September), predicting below-normal rainfall at 92% of the Long Period Average (LPA), with a model error of ±5%.
- The below-normal forecast is attributed to the development of El Niño conditions during the monsoon season, as predicted by IMD's Monsoon Mission Climate Forecast System (MMCFS).
- Regional exceptions exist: normal to above-normal rainfall is likely over northwest India and South Peninsular India.
- The Southwest Monsoon is expected to arrive over Kerala around 26 May 2026 — approximately five days ahead of the normal onset date of 1 June — due to favourable pre-monsoon conditions.
- The forecast has significant implications for Kharif crop planning, reservoir management, and drought preparedness across rain-dependent agricultural regions.
Static Topic Bridges
The Southwest Monsoon: Mechanism and Significance
The Southwest (SW) Monsoon is the primary rainfall system of India, responsible for about 70–75% of India's annual precipitation and critical for agriculture, hydropower, and groundwater recharge.
- Season: June 1 (normal Kerala onset) to September 30
- Mechanism: Driven by differential heating between the Indian landmass and the Indian Ocean. As the Indian subcontinent heats rapidly in summer, a low-pressure zone forms, drawing moisture-laden winds from the southwest off the Arabian Sea and Bay of Bengal.
- Two branches: (1) Arabian Sea branch — hits Kerala/Karnataka/Goa first, then moves north; (2) Bay of Bengal branch — hits northeast India/Bangladesh, then moves west
- Coverage: The monsoon normally covers the entire country by mid-July
- LPA (1971–2020): The Long Period Average of monsoon seasonal rainfall over India is 870 mm
- IMD Classification bands:
- Above Normal: 104–110% of LPA
- Normal: 96–104% of LPA
- Below Normal: 90–96% of LPA (the 2026 forecast at 92% falls here)
- Deficient: Below 90% of LPA
Connection to this news: IMD classifies the 2026 monsoon at 92% of LPA as 'below normal' — within the 90–96% range — meaning rainfall will be reduced but not classified as a drought (which requires <90% of LPA).
El Niño and Its Impact on the Indian Monsoon
El Niño is a climate phenomenon characterised by anomalous warming of sea surface temperatures (SST) in the central and eastern equatorial Pacific Ocean. It is part of the broader El Niño-Southern Oscillation (ENSO) cycle.
- El Niño → warmer Pacific SSTs → shifts atmospheric convection eastward → weakens the Walker Circulation → reduces moisture supply to the Indian subcontinent → below-normal monsoon in India
- La Niña (opposite of El Niño) → cooler Pacific SSTs → stronger Walker Circulation → favourable/above-normal monsoon in India
- ENSO Neutral: Neither El Niño nor La Niña conditions — monsoon outcome depends on other factors (Indian Ocean SSTs, MJO, etc.)
- Historical pattern: Major drought years in India (e.g., 2002, 2009, 2014) coincided with El Niño events; however, not all El Niño years produce deficient monsoon
- Indian Ocean Dipole (IOD): Another key modulator — positive IOD (warmer western Indian Ocean) typically compensates El Niño's negative impact; negative IOD amplifies dryness
Connection to this news: IMD's prediction of El Niño development during the 2026 monsoon season is the primary driver of the below-normal rainfall forecast.
IMD — Institutional Role and Forecasting Systems
The India Meteorological Department (IMD) is the national meteorological service under the Ministry of Earth Sciences.
- Established: 1875; headquartered in New Delhi
- Issues Long Range Forecasts (LRFs) in two stages: April (season-level) and June (updated with more lead time)
- Monsoon Mission Climate Forecast System (MMCFS): IMD's dynamical coupled ocean-atmosphere model used for seasonal forecasting; one of the most sophisticated operational monsoon prediction systems globally
- IMD also issues Extended Range Predictions (ERPs) for 2–4 week outlooks and short-range forecasts for agriculture and disaster management
- India's National Monsoon Mission (NMM), launched in 2012, aimed at improving monsoon forecasting skill at all timescales through modelling and international collaboration
Connection to this news: IMD's April LRF announcement is the first official government forecast for the 2026 monsoon, forming the basis for policy decisions in agriculture (MSP, sowing advisories), water resources (reservoir operations), and disaster risk management.
Monsoon and Indian Agriculture
India's Kharif cropping season (June–October) is directly dependent on the SW Monsoon. About 60% of India's net sown area is rain-fed.
- Key Kharif crops: Paddy (rice), Jowar, Bajra, Maize, Cotton, Groundnut, Soybean, Sugarcane
- Deficient/below-normal monsoon → reduced Kharif output → food inflation → rural distress → fiscal pressure on MSP operations
- Rabi season (October–March) is less monsoon-dependent but relies on soil moisture and reservoir levels carried forward from Kharif
- Drip irrigation, micro-irrigation (Pradhan Mantri Krishi Sinchayee Yojana — PMKSY) and crop insurance (Pradhan Mantri Fasal Bima Yojana — PMFBY) are key policy responses to monsoon variability
Connection to this news: A below-normal 2026 monsoon will directly affect Kharif sowing decisions, water reservoir levels heading into Rabi 2026-27, and food price trends.
Key Facts & Data
- 2026 SW Monsoon forecast: 92% of LPA (below normal category: 90–96%)
- LPA (1971–2020 base period): 870 mm
- Model error: ±5%
- Kerala onset forecast: ~26 May 2026 (normal: 1 June; 5 days early)
- Normal completion of monsoon over entire India: ~mid-July
- Primary climate driver: El Niño (developing conditions during June–September 2026)
- Normal to above-normal rainfall likely in: northwest India and South Peninsular India
- IMD established: 1875
- India's rain-fed agricultural area: ~60% of net sown area
- IMD's forecasting tool: MMCFS (Monsoon Mission Climate Forecast System)