Updated Long Range Forecast for the Southwest Monsoon Seasonal Rainfall during June–September, 2026 and Monthly Rainfall and Temperature Outlook for June 2026

1. At a Glance

• IMD's second-stage (updated) Long Range Forecast (LRF) for the Southwest Monsoon (SWM) June–September 2026, issued on 29 May 2026 by the Ministry of Earth Sciences (MoES) [S1].
• Forecast pegs all-India seasonal rainfall at 90% of LPA (±4%) — a "below normal" category — revised downward from the first-stage April forecast of 92% of LPA (±5%) [S1][S2].
• Issued using the Multi-Model Ensemble (MME) system built around IMD's Monsoon Mission Climate Forecasting System (MMCFS) [S1].
• Critical for UPSC: links macro-economy (kharif sowing, food inflation, reservoir storage), climate science (ENSO/IOD), and disaster management (heatwave/drought policy).

2. Why in the News

• IMD issued the updated LRF for SWM 2026 on 29 May 2026, downgrading the seasonal outlook to 90% of LPA and signalling a ~60% probability of a deficient season, with June 2026 likely to be hotter than normal over most of India [S1].

3. Background & Evolution

• IMD founded 1875; operational LRF for monsoon issued since 1886.
• 2003: IMD adopted a two-stage forecast strategy (April first stage, May/June updated) using an 8/10-parameter statistical model.
• 2007: Monsoon Mission launched by MoES to develop dynamical coupled-model forecasting.
• 2021: IMD shifted to a new strategy using the Multi-Model Ensemble (MME) combining CGCMs from global centres plus MMCFS [S1].
• 13 April 2026: First-stage 2026 SWM forecast issued (92% of LPA, ±5%) [S2].
• 29 May 2026: Updated forecast at 90% of LPA (±4%) plus June 2026 outlook [S1].

4. Core Static Facts

• Issuing body: India Meteorological Department (IMD), under Ministry of Earth Sciences [S1].
• Long Period Average (LPA) for SWM rainfall: 87 cm (1971–2020 base period) used by IMD.
• Five rainfall categories (% of LPA): Deficient <90; Below Normal 90–95; Normal 96–104; Above Normal 105–110; Excess >110.
• 2026 updated quantitative forecast: 90% of LPA, model error ±4% → "Below Normal" [S1].
• First-stage (April 2026) forecast: 92% of LPA ±5% [S2].
• June 2026 rainfall: Below normal over most of India; near/above normal over parts of NW India, NE India, eastern parts of south peninsula [S1].
• June 2026 temperature: Above-normal maximum temperatures likely over most parts of India except parts of south peninsula and east/northeast; higher-than-normal heatwave days in many areas [S1].
• Climate drivers: Neutral ENSO trending toward El Niño during the season; neutral IOD with positive IOD likely late season [S1].
• Core Monsoon Zone (CMZ) rainfall: <94% of LPA (below normal) [S1].

5. Multi-Dimensional Analysis

Economic - Below-normal monsoon threatens kharif output (paddy, pulses, oilseeds, cotton) — ~51% of net sown area is rain-fed; ~40% of food output depends on SWM. - Risk to rural demand, food inflation (CPI), reservoir storage for rabi sowing and hydropower.

Environmental / Scientific - ENSO–monsoon teleconnection: El Niño historically correlates with deficient Indian monsoons (e.g., 2002, 2009, 2015, 2023) [S1]. - Indian Ocean Dipole (IOD): positive IOD enhances SWM; its late-season onset limits its compensatory effect [S1]. - MME approach integrates CGCMs from multiple global centres + MMCFS → reduces single-model bias [S1].

Administrative / Governance - Crisis Management Plan (Drought) under DoLR/Ministry of Agriculture; NDMA heatwave guidelines become operative. - Inter-State Council & State Agriculture Depts use forecast for contingency cropping plans (ICAR-CRIDA).

Social - Rain-fed farmers, agricultural labour, MGNREGA demand typically spikes in deficient monsoon years. - Heatwave mortality risk in NW & Central India.

6. Recent Developments (last 12–18 months)

• 13 April 2026: IMD first-stage SWM forecast — 92% of LPA ±5% [S2].
• 29 May 2026: Updated forecast — 90% of LPA ±4%; June 2026 rainfall & temperature outlook released [S1].
• 2025 SWM: IMD had forecast above-normal rainfall (105% of LPA) — contrast to 2026's below-normal call.

7. Prelims Hooks

• IMD's updated SWM 2026 forecast: 90% of LPA (±4%) — Below Normal [S1].
• First-stage forecast (13 April 2026): 92% of LPA (±5%) [S2].
• Issuing ministry: Ministry of Earth Sciences (NOT MoEFCC) [S1].
• Forecast framework since 2021: Multi-Model Ensemble (MME) [S1].
• Indigenous model in MME: Monsoon Mission Climate Forecasting System (MMCFS) [S1].
• LPA reference period: 1971–2020; LPA value = 87 cm.
• "Normal" rainfall band: 96–104% of LPA.
• Core Monsoon Zone rainfall in 2026: <94% of LPA [S1].
• ENSO status (May 2026): Neutral, trending towards El Niño during season [S1].
• IOD status (May 2026): Neutral; positive IOD likely late season [S1].
• June 2026 all-India: Below-normal rainfall over most parts [S1].
• June 2026 temperature: Above-normal max temperature and more heatwave days over many regions [S1].
• IMD founded: 1875; under MoES since 2006.

8. Mains Relevance

• GS-I: Geography — Indian monsoon, factors influencing it (ENSO, IOD, MJO, snow cover).
• GS-III: Agriculture (cropping patterns, rain-fed farming, food security), Disaster Management (drought, heatwave), Science & Tech (climate modelling).
• Possible stems: 1. "Discuss how El Niño–Southern Oscillation (ENSO) and the Indian Ocean Dipole (IOD) jointly modulate the Indian summer monsoon. (15M)" 2. "Evaluate the role of the Monsoon Mission and Multi-Model Ensemble system in improving the reliability of India's long-range monsoon forecasts. (10M)" 3. "A below-normal monsoon poses cascading risks across agriculture, inflation and rural livelihoods. Suggest a policy roadmap to build climate resilience in Indian agriculture. (15M)"

9. Related Topics to Study Next

• Monsoon Mission (MoES, 2012) — funding & institutional base for MMCFS.
• ENSO, La Niña, El Niño, MJO, Madden–Julian Oscillation — climate drivers.
• PM Fasal Bima Yojana (PMFBY) — risk transfer for monsoon-linked crop losses.
• PMKSY (Pradhan Mantri Krishi Sinchayee Yojana) — irrigation buffer to monsoon risk.
• NDMA Heatwave Action Plans — disaster-management overlap.
• Central Water Commission Reservoir Bulletin — reservoir storage tracking.
• ICAR-CRIDA contingency crop plans — drought-proofing.
• India's NDC and climate-resilient agriculture — long-term adaptation.

10. Common Errors / Trap Areas

• Wrong ministry: IMD is under MoES, not MoEFCC or Ministry of Agriculture.
• LPA confusion: LPA value (~87 cm) often confused with the % figure; current base period is 1971–2020, not 1961–2010.
• Category bands: "Below Normal" = 90–95%; "Deficient" = <90% — easily swapped.
• First-stage vs updated forecast: 92% (April) vs 90% (May 2026) — examiners may juxtapose.
• El Niño ≠ guaranteed drought: it raises probability but is not deterministic; positive IOD can offset.

11. Sources

• [S1] Updated Long Range Forecast for the Southwest Monsoon Seasonal Rainfall during June–September, 2026 and Monthly Rainfall and Temperature Outlook for June 2026 — https://www.pib.gov.in/PressReleasePage.aspx?PRID=2266479 — (tier: 1)
• [S2] Long Range Forecast For the 2026 Southwest Monsoon Season Rainfall (first stage, 13 April 2026) — https://www.pib.gov.in/PressReleasePage.aspx?PRID=2251594 — (tier: 1)