What Happened
- The India Meteorological Department (IMD) has forecast that the 2026 southwest monsoon (June–September) is likely to be "below normal," with seasonal rainfall at approximately 92% of the Long Period Average (LPA), with a model error of ±5%.
- The IMD's Monsoon Mission Climate Forecast System (MMCFS) indicates that El Niño conditions are likely to develop during the monsoon season, particularly after June 2026, which could further suppress rainfall.
- Current Pacific Ocean conditions are transitioning from weak La Niña to ENSO-neutral; a positive Indian Ocean Dipole (IOD) is expected to develop toward the later part of the monsoon season, which may partially offset El Niño's negative influence.
- The below-normal forecast raises concern for kharif agriculture, food prices, and rural demand — sectors heavily dependent on monsoon performance.
- IMD classifies monsoon rainfall as: "above normal" (>104% LPA), "normal" (96–104%), "below normal" (90–95%), and "deficient" (<90% LPA).
Static Topic Bridges
India Meteorological Department (IMD)
IMD is India's national meteorological service, established in 1875 under the Ministry of Earth Sciences. It is the apex body responsible for weather observation, forecasting, and early warning across India. IMD issues long-range forecasts for the southwest monsoon — the most critical weather event for India's agriculture, water security, and economy.
- Established: 1875; Headquarters: New Delhi
- Parent Ministry: Ministry of Earth Sciences
- Issues two-stage Long Range Forecast (LRF): first in April, updated in June
- Uses the Monsoon Mission Climate Forecast System (MMCFS) — a coupled ocean-atmosphere model — alongside statistical methods and Multi-Model Ensemble (MME) approaches
- LPA for all-India summer monsoon rainfall (1971–2020 baseline): 868.6 mm
Connection to this news: IMD's April 2026 forecast of 92% LPA places this monsoon in the "below normal" category and triggers early agricultural advisories across ministries.
Long Period Average (LPA) and Monsoon Classification
The LPA is the average monsoon rainfall computed over a standard 50-year reference period. IMD updates this baseline periodically; the current LPA (1971–2020) is 868.6 mm for the June–September season over the whole country. Monsoon forecasts are expressed as a percentage of the LPA.
- Above Normal: >104% of LPA
- Normal: 96–104% of LPA
- Below Normal: 90–95% of LPA
- Deficient: <90% of LPA
- Excess: >110% of LPA
Connection to this news: At 92% of LPA, the 2026 monsoon sits in the "below normal" band, meaning approximately 797–825 mm of rainfall — roughly 44–70 mm less than average.
El Niño–Southern Oscillation (ENSO) and Indian Monsoon
ENSO is a coupled ocean-atmosphere phenomenon in the tropical Pacific that modulates India's monsoon through the Walker Circulation. During El Niño, Pacific trade winds weaken, warm water spreads eastward, reducing convection over the western Pacific and weakening moisture transport into the Indian subcontinent — typically suppressing monsoon rainfall.
- El Niño years historically associated with below-normal monsoon in India; roughly 6 out of 10 El Niño years see deficient or below-normal rainfall
- The relationship is stronger over peninsular and northwest India than central India
- La Niña tends to enhance Indian monsoon rainfall
- The spring predictability barrier (March–May) limits ENSO forecast accuracy for the full monsoon season
Connection to this news: IMD warns that El Niño conditions likely to develop post-June 2026 could intensify rainfall deficiency, especially in the second half of the monsoon (August–September).
Indian Ocean Dipole (IOD)
The IOD is an ocean-atmosphere interaction in the Indian Ocean, measured as the difference in sea surface temperatures (SST) between the western and eastern Indian Ocean. A positive IOD (warmer western, cooler eastern Indian Ocean) enhances moisture availability over India and can partially counteract El Niño's suppressive effect on the monsoon.
- Positive IOD: boosts Indian monsoon rainfall by 10–20% in good years
- Negative IOD: diverts moisture toward Indonesia, weakening Indian rainfall
- IOD and ENSO can interact — positive IOD sometimes acts as a buffer during El Niño years
- Monitored via the Dipole Mode Index (DMI)
Connection to this news: IMD anticipates a positive IOD developing toward the end of the 2026 monsoon season, which may provide partial relief in October though the core June–September deficit may persist.
Key Facts & Data
- 2026 monsoon forecast: 92% of LPA (±5%), classified as "below normal"
- LPA (1971–2020 baseline): 868.6 mm (June–September, all-India)
- El Niño conditions expected to develop after June 2026
- Southwest monsoon accounts for approximately 75% of India's annual rainfall
- Nearly 50% of India's farmland is rain-fed and directly dependent on the monsoon
- Kharif crops at risk: rice, pulses, oilseeds, cotton, sugarcane, groundnut
- IMD's forecast accuracy within ±5% of LPA has been 100% for 2021–2024
- Skymet (private forecaster) independently predicted 94% of LPA for 2026