Why in News
🗞️ Why in News
India’s southwest monsoon opened June 2026 with a rainfall deficit of about 40 per cent, attributed to a strengthening El Nino, an unfavourable phase of the Madden-Julian Oscillation (MJO) and a lack of monsoon low-pressure systems. On June 30, 2026, the India Meteorological Department (IMD) reported the monsoon’s advance into several central and northern regions.
A deficit-opening monsoon under El Nino conditions is exam-relevant on two fronts: the atmospheric-ocean physics that modulates the monsoon (GS1 geography) and the downstream consequences for agriculture, water storage and food security (GS3). This article unpacks both.
The June 2026 Picture
Against the seasonal average, June opened dry. Central India recorded the sharpest shortfall. The IMD, India’s nodal forecasting agency, tracks the monsoon’s northward advance through pre-defined lines, and on June 30, 2026 it reported advance into new territory.
| Item | Detail |
|---|---|
| June 2026 opening deficit | About 40 per cent below normal |
| Primary drivers | Strengthening El Nino, unfavourable MJO phase, missing low-pressure systems |
| Nodal agency | India Meteorological Department (IMD) |
| Normal onset over Kerala | Around June 1 |
| Share of annual rainfall | Roughly 70 per cent from the southwest monsoon |
On June 30, 2026, the IMD reported that the monsoon had advanced into more of Madhya Pradesh, the remaining parts of Chhattisgarh, Jharkhand and Bihar, parts of Uttar Pradesh, most of Uttarakhand, and parts of Himachal Pradesh and Ladakh.
The Science: ENSO and MJO
El Nino and ENSO
El Nino is the warm phase of the El Nino Southern Oscillation (ENSO), a coupled ocean-atmosphere phenomenon in the equatorial Pacific. During El Nino, the central and eastern Pacific warms, shifting the zone of intense convection eastward, away from the Indian and western Pacific region. This tends to weaken the pressure gradient that drives moisture toward the Indian subcontinent, so El Nino years are statistically associated with a suppressed or below-normal Indian monsoon (though not every El Nino year is a drought year). The opposite phase, La Nina, generally favours a stronger monsoon; neutral conditions lie in between.
The Madden-Julian Oscillation
The Madden-Julian Oscillation (MJO) is an eastward-moving pulse of enhanced and suppressed tropical rainfall that circles the globe on a roughly 30 to 60 day cycle. When the MJO’s wet (active) phase sits over the Indian Ocean, it boosts monsoon rainfall; when its dry (suppressed) phase dominates the region, rainfall falters. In June 2026 the MJO was in an unfavourable phase, reinforcing the El Nino-driven suppression.
Low-Pressure Systems and Depressions
Much of the seasonal rainfall is actually delivered not by the broad monsoon current alone but by monsoon low-pressure systems and depressions, which form over the Bay of Bengal and track inland, wringing out heavy rain along their path. A season starved of these systems, as in early monsoon 2026, sees rainfall concentrate poorly and totals fall short even where the monsoon has “arrived” on the map.
Analysis and Way Forward
The physical drivers are largely beyond policy control, so resilience must come from preparedness. The southwest monsoon delivers roughly 70 per cent of India’s annual rainfall and underwrites kharif sowing, reservoir filling and hydropower storage; a front-loaded deficit stresses sowing windows for paddy, pulses and coarse cereals, and can pull down reservoir levels heading into the lean season.
The way forward combines short-term and structural measures: IMD’s extended-range and MJO-based forecasts should feed advisories that let farmers adjust crop choice and sowing dates; states should stagger reservoir releases conservatively; contingency crop plans and assured seed supply of short-duration, drought-tolerant varieties should be ready; and demand-side water efficiency (micro-irrigation, aquifer recharge under schemes such as watershed and Jal Shakti programmes) reduces exposure to any single deficit year. A recovery in rainfall through July and August, driven by a favourable MJO swing or the arrival of Bay of Bengal depressions, can still narrow the seasonal gap, so early deficits are a warning, not a verdict.
UPSC Relevance
GS Paper 1: Important geophysical phenomena; the Indian monsoon mechanism; factors affecting the climate of India.
GS Paper 3: Agriculture and food security; issues related to water resources; disaster management and drought preparedness.
Prelims pointers:
- El Nino is the warm phase of ENSO; it tends to suppress the Indian monsoon. La Nina generally strengthens it.
- MJO is an eastward-moving tropical rainfall pulse with a roughly 30 to 60 day cycle.
- IMD is the nodal forecasting agency; normal monsoon onset over Kerala is around June 1.
- The southwest monsoon delivers roughly 70 per cent of India’s annual rainfall.
- Monsoon low-pressure systems and depressions drive much of the seasonal rain.
Mains question: Explain how the El Nino Southern Oscillation and the Madden-Julian Oscillation modulate the Indian southwest monsoon, and discuss the food-security implications of a deficit monsoon year. (15 marks, 250 words)
Facts Corner
📌 Facts Corner, Knowledgepedia
- Deficit: June 2026 monsoon opened about 40 per cent below normal.
- Drivers: Strengthening El Nino, unfavourable MJO phase, lack of low-pressure systems.
- El Nino: Warm phase of the El Nino Southern Oscillation (ENSO); suppresses the Indian monsoon.
- MJO: Eastward-moving tropical rainfall pulse, roughly 30 to 60 day cycle.
- IMD: Nodal forecasting agency; normal onset over Kerala around June 1.
- June 30, 2026 advance: More of Madhya Pradesh; remaining Chhattisgarh, Jharkhand and Bihar; parts of Uttar Pradesh; most of Uttarakhand; parts of Himachal Pradesh and Ladakh.
- Significance: Southwest monsoon delivers roughly 70 per cent of India’s annual rainfall; critical for kharif sowing and reservoir and hydropower storage.
Sources: India Meteorological Department, Down To Earth, Ministry of Earth Sciences
Source: Monsoon 2026 Opens with a Rainfall Deficit Under El Nino Shadow — Ujiyari.com | Free UPSC & State PCS Current Affairs
