Heatwave grips India: WMO flags El Niño by mid-2026; IMD warns of below-normal monsoon
The World Meteorological Organisation (WMO) has forecast El Niño conditions likely to emerge between May and July 2026, with climate models showing high conf...
What Happened
- The World Meteorological Organisation (WMO) has forecast El Niño conditions likely to emerge between May and July 2026, with climate models showing high confidence in the onset and subsequent intensification.
- India is experiencing severe heatwave conditions, with Banda in Uttar Pradesh recording 47.4°C — the highest temperature recorded in the country this year; Maharashtra's Vidarbha region and parts of Rajasthan, Haryana, and Odisha have also reported extreme heat.
- The India Meteorological Department (IMD) has issued a below-normal monsoon forecast for the 2026 southwest monsoon season (June–September), projecting seasonal rainfall at approximately 92% of the Long Period Average (LPA), with a model error of ±5%.
- This would be the first below-normal monsoon in three years, coming after two consecutive years of above-normal rainfall.
- Authorities in heat-affected states have issued advisories, activated heat action plans, and instructed hospitals to prepare for heat-related illness cases.
Static Topic Bridges
El Niño–Southern Oscillation (ENSO) and the Walker Circulation
El Niño–Southern Oscillation (ENSO) is a periodic climate phenomenon originating in the tropical Pacific Ocean. Under normal conditions, trade winds blow westward along the equator, piling up warm water in the western Pacific and maintaining cooler sea surface temperatures (SSTs) in the eastern Pacific — a pattern driven by the Walker Circulation (an east–west atmospheric overturning cell). During El Niño, trade winds weaken, warm water spreads eastward, and the Walker Circulation reverses or weakens, altering rainfall and temperature patterns globally. La Niña is the opposite phase — stronger trade winds, cooler eastern Pacific, enhanced rainfall over South Asia.
- ENSO is the largest single driver of year-to-year variability in Indian monsoon rainfall.
- During El Niño, anomalous atmospheric subsidence forms over the Indian subcontinent, suppressing convection and weakening the southwest monsoon — historically associated with drought years in India (e.g., 2002, 2009).
- During La Niña, the opposite effect tends to strengthen the southwest monsoon.
- The Inter-Tropical Convergence Zone (ITCZ) — the low-pressure belt that drives monsoon onset — shifts southward during strong El Niño events, delaying or weakening the monsoon trough over India.
- IITM Pune (Earth System Science Organisation, under MoES) conducts advanced ENSO monitoring and seasonal forecasting for India.
Connection to this news: WMO's forecast of El Niño emergence by mid-2026 directly underpins IMD's below-normal monsoon projection, as El Niño-induced Walker Circulation weakening is expected to suppress southwest monsoon rainfall.
IMD Heatwave Definition and Classification
The India Meteorological Department defines a heatwave using specific quantitative thresholds based on station type and departure from normal maximum temperatures.
- Plains stations: Heat wave is declared when maximum temperature reaches at least 40°C AND departs from normal by 4°C–5°C (heatwave) or 6°C or more (severe heatwave); OR when actual maximum temperature is 45°C or above irrespective of normal.
- Hilly stations: Temperature threshold is 30°C with the same departure criteria.
- Coastal stations: Temperature of 37°C OR a departure of 4.5°C above normal qualifies.
- A heatwave is officially declared when conditions persist at at least 2 stations in a meteorological subdivision for two consecutive days.
- Heat action plans (HAPs) are India's key disaster-management tool for heatwaves — coordinated at district and state levels with pre-defined response protocols.
Connection to this news: The current spell meets multiple IMD heatwave thresholds across plains stations, with temperatures exceeding 45°C in some areas, qualifying as severe heatwaves.
World Meteorological Organisation (WMO)
The WMO is a specialised agency of the United Nations responsible for international cooperation in meteorology, climatology, hydrology, and related fields.
- Full name: World Meteorological Organization
- Headquarters: Geneva, Switzerland
- Established: Convention entered into force on 23 March 1950; WMO became a UN specialised agency in 1951.
- Membership: 193 member states and territories.
- Key function: Issues global climate forecasts and El Niño/La Niña alerts; coordinates the Global Climate Observing System (GCOS); publishes annual State of the Global Climate reports.
- India is a member and IMD operates within the WMO framework for international data sharing.
Connection to this news: The WMO's official seasonal forecast for El Niño onset by May–July 2026 forms the scientific basis for national-level heat preparedness and monsoon management planning.
Key Facts & Data
- WMO forecasts El Niño conditions emerging between May and July 2026.
- IMD projects 2026 southwest monsoon at 92% of Long Period Average (LPA) — below normal range.
- Banda, Uttar Pradesh recorded 47.4°C — highest temperature in India in 2026 so far.
- IMD heatwave threshold for plains: minimum 40°C AND 4°C–5°C above normal; severe heatwave at 45°C or 6°C+ above normal.
- WMO established: 23 March 1950; HQ: Geneva, Switzerland; UN specialised agency since 1951.
- ENSO mechanism: weakened Walker Circulation during El Niño → anomalous subsidence over India → suppressed southwest monsoon.
- 2026 would be the first below-normal monsoon year in India in three consecutive years.
- IITM Pune (Earth System Science Organisation, MoES) is India's lead ENSO research institution.