Why in News
India’s Southwest Monsoon officially made landfall in Kerala on June 4, 2026, the India Meteorological Department (IMD) confirmed. The arrival was three days behind the IMD’s own updated forecast and approximately on the normal onset date (June 1). The IMD simultaneously issued a forecast for a below-normal monsoon season — projecting 90–95% of the Long Period Average (LPA) rainfall for June–September 2026. The forecast is overshadowed by a developing El Niño event that meteorologists warn could intensify through the second half of the monsoon season.
What Is the Southwest Monsoon?
The Southwest Monsoon (June–September) is the primary rainy season for India, accounting for approximately 70–75% of India’s annual rainfall. It originates over the warm waters of the Arabian Sea and Bay of Bengal, driven by the differential heating of land and sea during summer.
Onset and Withdrawal Dates (Normal)
| Location | Normal Onset | Normal Withdrawal |
|---|---|---|
| Kerala | June 1 | — |
| Northeast India | June 5–10 | — |
| Delhi/NCR | June 27 | — |
| Mumbai | June 10 | — |
| Northwest India | July 15 | September 1 |
| Entire India | July 15 | October 15 |
IMD 2026 Forecast
| Parameter | Forecast |
|---|---|
| Total seasonal rainfall | 90–95% of LPA |
| LPA (1971–2020 average) | 87 cm |
| Classification | Below normal (< 96% of LPA) |
| El Niño conditions | Developing — risk of intensification July–August |
| Most at-risk regions | Northwest India (UP, Delhi, Punjab, Rajasthan) |
| Best performing region | Northeast India and Eastern India (relatively normal) |
Below normal is defined by IMD as rainfall between 90–95% of the LPA. A deficient monsoon (<90% LPA) triggers drought protocols under NDMA guidelines.
El Niño — The Key Risk Factor
El Niño is a periodic warming of the central and eastern equatorial Pacific Ocean that occurs every 2–7 years. It disrupts the Walker Circulation — the atmospheric system that drives monsoon moisture over the Indian subcontinent.
El Niño → Indian Monsoon Impact
| El Niño Strength | Typical Impact on Indian Monsoon |
|---|---|
| Weak | Marginal deficit (5–10%) |
| Moderate | Below-normal to deficient (-10 to -20%) |
| Strong | Severe drought risk (>-20%) |
Historical strong El Niño years that caused poor monsoons in India: 1972, 1987, 1997, 2002, 2009.
The 2026 El Niño is classified as moderate and intensifying by NOAA and IMD. Down to Earth (June 4, 2026) flagged scientific concern that it could rival the historic 1876–78 El Niño which caused catastrophic famines across South Asia.
Impact on Agriculture and Food Security
India’s kharif crops — sown between June and September — are directly dependent on the Southwest Monsoon. Key kharif crops include:
| Crop | Key States | Monsoon Dependency |
|---|---|---|
| Rice (paddy) | West Bengal, UP, Punjab, Odisha | High |
| Maize | Karnataka, Maharashtra, MP | High |
| Soybean | MP, Maharashtra | Very high |
| Pulses (arhar, urad, moong) | UP, MP, Maharashtra, Rajasthan | Very high |
| Cotton | Gujarat, Maharashtra, Telangana | Moderate-High |
| Sugarcane | UP, Maharashtra | Moderate |
| Groundnut | Gujarat, Rajasthan, AP | High |
A below-normal monsoon raises risks of:
- Lower kharif output → food price inflation, especially in pulses and vegetables
- Reduced reservoir storage → water stress in rabi season (October–March)
- Groundwater depletion → long-term agricultural vulnerability
- Rural income stress → reduced consumer demand in rural India
IMD Forecast Accuracy
IMD uses a multi-model ensemble approach and issues forecasts in two stages: the April Long-Range Forecast (first estimate) and the Updated May Forecast (revised). The May forecast has typically been more accurate. The current 90–95% forecast was issued in the updated May forecast cycle.
UPSC Relevance
Prelims
- SW Monsoon onset in Kerala: June 4, 2026 (normal: June 1)
- IMD 2026 forecast: 90–95% of LPA (below normal)
- LPA: 87 cm (1971–2020 average)
- El Niño: developing, moderate and intensifying
- Below-normal definition: 90–95% of LPA
- Deficient: < 90% of LPA; Excess: > 110% of LPA
Mains Angles
- GS1 — Physical Geography: Explain the mechanism of the Southwest Monsoon. How does El Niño disrupt monsoon circulation over the Indian subcontinent?
- GS3 — Food Security: Examine the implications of a below-normal monsoon for India’s kharif agricultural output, food inflation, and rural economy.
- GS3 — Disaster Management: What policy measures should India activate when monsoon forecasts indicate below-normal rainfall?
Facts Corner
| Fact | Detail |
|---|---|
| Monsoon arrival (Kerala) | June 4, 2026 |
| IMD forecast | 90–95% of LPA (below normal) |
| LPA (1971–2020) | 87 cm |
| El Niño status | Developing; moderate and intensifying |
| Most at-risk region | Northwest India |
| Key kharif crops at risk | Pulses, soybean, paddy |
| IMD classification of “below normal” | 90–95% of LPA |
| IMD classification of “deficient” | < 90% of LPA |
Source: Southwest Monsoon Arrives Kerala — IMD Forecasts Below-Normal Season Amid El Niño — Ujiyari.com | Free UPSC & State PCS Current Affairs
