What Happened
- The India Meteorological Department (IMD) has forecast the 2026 southwest monsoon (June–September) to be "below normal," with seasonal rainfall at approximately 92% of the Long Period Average (LPA).
- IMD specifically flagged that El Niño conditions are likely to develop after June 2026, which historically correlates with suppressed Indian monsoon rainfall.
- Historically, six out of ten El Niño years have been linked to depressed Indian monsoon rainfall, making this forecast particularly significant for agriculture-dependent regions.
- The forecast covers all-India seasonal rainfall; regional distribution may be more uneven, with states like Punjab, Haryana, Rajasthan, and parts of central India at greater risk of below-normal rainfall.
- A positive Indian Ocean Dipole (IOD) is expected toward the tail end of the monsoon season (September–October), which may provide partial offsetting support.
Static Topic Bridges
India Meteorological Department (IMD): Role and Forecasting Framework
The IMD is India's apex body for meteorological observation, research, and forecasting, established in 1875 and functioning under the Ministry of Earth Sciences. Its Long Range Forecast (LRF) for the southwest monsoon — issued in two stages (April and June) — is the most consequential seasonal forecast in Indian public policy, influencing agriculture, water management, power, and fiscal planning.
- Established: 1875; current headquarters: New Delhi (Mausam Bhawan)
- Ministry: Ministry of Earth Sciences
- Two-stage LRF: Stage 1 (April) for seasonal rainfall; Stage 2 (June) with updated regional forecast
- Forecast model: Monsoon Mission Climate Forecast System (MMCFS) + Multi-Model Ensemble (MME) + statistical methods
- Long Period Average (LPA): 868.6 mm for June–September (1971–2020 reference period)
Connection to this news: IMD's April 2026 forecast places the monsoon at 92% of LPA — in the "below normal" category — with El Niño risk explicitly cited as the primary driver of concern.
ENSO Phases and the Indian Monsoon Teleconnection
The El Niño–Southern Oscillation (ENSO) is the dominant year-to-year driver of Indian monsoon variability. ENSO operates from the tropical Pacific but influences Indian rainfall through large-scale atmospheric circulation patterns (Walker and Hadley Circulations). El Niño events warm the eastern Pacific, shift rainfall patterns globally, and reduce the moisture supply available to the Indian monsoon.
- El Niño: anomalous warming of Nino 3.4 region (5°N–5°S, 170°W–120°W) by ≥0.5°C for ≥5 consecutive overlapping 3-month periods
- La Niña (opposite phase): typically enhances Indian monsoon
- ENSO-neutral: no significant impact on monsoon
- Six out of 10 El Niño years: below-normal or deficient Indian monsoon (IMD data)
- Worst drought years correlated with El Niño: 1987, 2002, 2009, 2015
Connection to this news: El Niño developing post-June 2026 aligns with the second half of the monsoon season (August–September) — the critical period for late kharif crops — raising risk of uneven or deficient rainfall in vulnerable zones.
Monsoon and Climate Classification of India
India's diverse climate is fundamentally shaped by the southwest monsoon, which determines agricultural productivity, river hydrology, and groundwater recharge. The Koppen climate classification places most of India under tropical savanna (Aw) and humid subtropical (Cwa) types, both highly monsoon-dependent. The IMD uses its own rainfall classification system based on percentages of the LPA.
- IMD monsoon classification bands:
- Excess: >110% LPA
- Above Normal: 104–110% LPA
- Normal: 96–104% LPA
- Below Normal: 90–95% LPA
- Deficient: <90% LPA
- Regional variation: western coast, northeast India receive >2,500 mm; Rajasthan <300 mm
- States most sensitive to below-normal monsoon: Maharashtra, Karnataka, Rajasthan, Madhya Pradesh, Uttar Pradesh (rain-fed agriculture dominance)
Connection to this news: At 92% LPA, the 2026 forecast places India in the "below normal" band — historically associated with localized drought conditions in rain-fed agricultural belts, stress on reservoir storage, and kharif crop yield reduction.
Madden-Julian Oscillation (MJO) and Intra-Seasonal Variability
Beyond ENSO, the Madden-Julian Oscillation (MJO) significantly influences intra-seasonal variability of the Indian monsoon — the week-to-week and month-to-month fluctuations within the monsoon season. An active MJO can bring "breaks" or "active spells" in monsoon rainfall independent of ENSO conditions.
- MJO: an eastward-moving atmospheric disturbance with a 30–60 day cycle
- Active MJO phase over Indian Ocean: boosts Indian monsoon rainfall
- Suppressed MJO phase: causes monsoon "break" periods
- IMD monitors MJO as a key sub-seasonal factor alongside ENSO and IOD
Connection to this news: Even in below-normal years, MJO active phases can deliver episodic heavy rainfall events; drought conditions typically emerge when extended MJO suppression coincides with El Niño.
Key Facts & Data
- IMD 2026 southwest monsoon forecast: 92% of LPA (±5%)
- "Below normal" classification: 90–95% of LPA
- El Niño conditions expected to develop after June 2026
- Six out of 10 El Niño years historically associated with below-normal Indian monsoon (IMD)
- LPA (1971–2020): 868.6 mm (June–September, all-India)
- Positive IOD expected to develop toward end of 2026 monsoon season
- Southwest monsoon: ~75% of India's annual rainfall
- States at higher risk: Punjab, Haryana, Rajasthan, central India (Madhya Pradesh, Vidarbha)
- IMD forecast accuracy within ±5% LPA: 100% over 2021–2024