Why in News: The India Meteorological Department (IMD) issued a yellow heatwave alert for Delhi-NCR on May 19, 2026, with maximum temperatures recorded at 43–45°C across the capital region. IMD simultaneously issued an orange alert (severe heatwave) for Wardha and Yavatmal districts of Vidarbha, Maharashtra. The northwest India plains — including Rajasthan, UP, Haryana, and Punjab — are forecast to remain under heatwave to severe heatwave conditions until May 24. IMD also confirmed that the Southwest Monsoon onset over Kerala remains on track for May 26, 2026 — five days ahead of the normal date of June 1.
Delhi Heatwave — May 19, 2026
| Parameter | Data |
|---|---|
| Maximum temperature (Delhi) | 43–45°C (recorded May 19) |
| Normal maximum for May 19 | ~40°C |
| Departure from normal | +3 to +5°C |
| IMD alert level | Yellow (heatwave — temperature ≥40°C; 4.5°C above normal) |
| Duration forecast | Until May 24, 2026 |
| Relative humidity | 10–20% (very dry; typical pre-monsoon conditions) |
| Hottest station | Barmer, Rajasthan (~48°C) |
Heatwave Classification (IMD Standards)
| Category | Plain stations (below 1,000m) | Coastal stations | Hills (above 1,000m) |
|---|---|---|---|
| Heatwave | Max temp ≥40°C AND ≥4.5°C above normal | Max temp ≥37°C AND ≥4.5°C above normal | Max temp ≥30°C AND ≥4.5°C above normal |
| Severe heatwave | Max temp ≥40°C AND ≥6.5°C above normal | Max temp ≥37°C AND ≥6.5°C above normal | Max temp ≥30°C AND ≥6.5°C above normal |
| Extreme heatwave | Max temp ≥45°C | Max temp ≥41°C | — |
Delhi’s 43–45°C with 3–5°C above normal qualifies as a heatwave (yellow alert). Barmer’s ~48°C qualifies as an extreme heatwave.
Vidarbha Orange Alert — Maharashtra
| District | Alert Level | Details |
|---|---|---|
| Wardha | Orange (severe heatwave) | Max 44–46°C; 6.5°C above normal |
| Yavatmal | Orange (severe heatwave) | Max 44–46°C; 6.5°C above normal |
| Nagpur | Yellow | Max 42–43°C |
| Akola | Yellow | Max 43–44°C |
Vidarbha is Maharashtra’s most heat-prone inland region — cotton-growing belt, low tree cover, and proximity to the Deccan Plateau’s hot air mass make it vulnerable to extreme pre-monsoon heat.
IMD Alert Colour Code
| Colour | Meaning | Action |
|---|---|---|
| Green | No warning | Watch |
| Yellow | Be Aware — heatwave | Watch and prepare |
| Orange | Be Prepared — severe heatwave | Alert; action likely needed |
| Red | Take Action — extreme heatwave | Immediate action required |
Southwest Monsoon — 2026 Outlook
Onset Forecast: Kerala May 26
IMD’s forecast for Southwest Monsoon onset over Kerala: May 26, 2026 — five days earlier than the normal date of June 1.
| Parameter | 2026 Status |
|---|---|
| SW Monsoon onset Kerala | May 26 (normal: June 1; 5 days early) |
| Seasonal rainfall (June–September) | 92% of Long Period Average (LPA) — classified as Below Normal |
| LPA (1971–2020 baseline) | ~868.6 mm for the country as a whole |
| Below Normal definition | 90–95% of LPA |
| El Niño probability (June–August) | High (NOAA ~62%; PAGASA ~79%) — a key factor suppressing rainfall |
Why Early Onset?
- The Mascarene High (pressure system over Indian Ocean) has strengthened earlier than normal, pumping moisture northward
- Arabian Sea branch of the monsoon is building strength; Bay of Bengal branch on schedule
- However, despite early onset, total seasonal rainfall is forecast at 92% LPA — early does not mean bountiful
El Niño Impact
El Niño (warm SST anomaly in central-eastern equatorial Pacific) is associated with below-normal monsoon rainfall in India:
| El Niño Phase | Effect on India Monsoon |
|---|---|
| El Niño active | Below Normal to Deficient rainfall (historically) |
| La Niña active | Above Normal to Normal rainfall |
| ENSO Neutral | Normal rainfall |
El Niño probability for June–August 2026 is high (NOAA: ~62%; PAGASA: ~79%), which explains the 92% LPA forecast. Notable below-normal monsoon years linked to El Niño: 1987, 2002, 2009, 2014.
IMD Alert System and Heat Action Plans
National Disaster Management Authority (NDMA) Guidelines
- Heat Action Plans (HAPs): All states/UTs mandated to have HAPs; district-level coordination
- National Heat Portal: Real-time heat health alert system
- Vulnerable populations: outdoor workers, elderly, infants, people with chronic illness
- NIMHANS + ICMR coordination for heat-health surveillance
- Ahmedabad HAP (est. 2013): India’s pioneering city-level HAP; model for other cities; run by IIPH (Indian Institute of Public Health, Gandhinagar) in partnership with AMC (Ahmedabad Municipal Corporation)
IMD Forecast Services
| Service | Detail |
|---|---|
| National Weather Forecasting Centre (NWFC) | 24×7 operational centre; Delhi; issues national forecasts |
| Extended Range Forecast (ERF) | 3–4 week outlook; issued weekly |
| Seasonal Forecast | April–June issued in April; June–September issued in April and updated in May |
| District-level forecasts | 5-day district-wise weather forecasts for all 700+ districts |
| Agri-Met services | Weekly agro-meteorological bulletins for farmers (in collaboration with IMD and ICAR) |
Northeast India — Contrasting Conditions
While northwest India burns, Northeast India is seeing the opposite extreme on May 19:
- Assam, Meghalaya, Arunachal Pradesh: Heavy to very heavy rainfall + thunderstorms forecast
- Brahmaputra flood season: Pre-monsoon rains causing early flash floods in Assam’s flood plains
- Cyclone risk: Bay of Bengal heating up — IMD monitoring for potential pre-monsoon cyclone development
Urban Heat Island Effect: Delhi-NCR
Delhi’s temperatures are exacerbated by the Urban Heat Island (UHI) effect:
- Concrete, asphalt, and reduced green cover trap solar radiation
- Delhi’s green cover is ~20% of city area — below the 33% norm for Indian cities
- Air conditioning units release waste heat — creating a feedback loop
- UHI can add 2–5°C to city temperatures relative to surrounding rural areas
Delhi Heat Action Plan (DHAP): Delhi has a Heat Action Plan but its implementation has been criticised as inadequate — cooling centres are limited, worker protections weak.
UPSC Relevance
GS Paper 3 — Disaster Management / Environment
- Heatwave classification: IMD’s criteria for heatwave, severe heatwave, extreme heatwave; colour-coded alert system
- Monsoon: SW monsoon onset; LPA; El Niño–monsoon linkage; below-normal classification
- Urban Heat Island effect: causes, consequences, mitigation
- Heat Action Plans: NDMA guidelines; Ahmedabad model; cooling centres
GS Paper 1 — Geography
- SW monsoon: onset, withdrawal, progress across India; role of Mascarene High, Arabian Sea branch, Bay of Bengal branch
- Vidarbha: geographic characteristics; heat vulnerability
Keywords: IMD, yellow alert, heatwave, Delhi-NCR, Vidarbha, orange alert, SW Monsoon onset, Kerala, LPA, Below Normal, El Niño, Mascarene High, Urban Heat Island, Heat Action Plan, NDMA.
Sources: Business Standard, IMD, PIB
📌 Facts Corner — Knowledgepedia
Heatwave — Delhi-NCR (May 19, 2026):
- Max temperature: 43–45°C (3–5°C above normal)
- IMD alert: Yellow (heatwave)
- Hottest in India: Barmer, Rajasthan (~48°C; extreme heatwave)
- Maharashtra: Orange alert for Wardha and Yavatmal (Vidarbha) — severe heatwave
IMD Heatwave Classification:
- Heatwave: Max temp ≥40°C AND ≥4.5°C above normal (plain stations)
- Severe heatwave: Max temp ≥40°C AND ≥6.5°C above normal
- Extreme heatwave: Max temp ≥45°C
IMD Alert Colours:
- Green = watch | Yellow = be aware | Orange = be prepared | Red = take action
SW Monsoon 2026:
- Onset over Kerala: May 26, 2026 (normal: June 1; 5 days early)
- Seasonal forecast: 92% of LPA = Below Normal rainfall
- LPA (1971–2020): ~868.6 mm (India average, June–September)
- Below Normal definition: 90–95% of LPA
- El Niño probability (Jun–Aug 2026): High — NOAA ~62%; PAGASA ~79% — primary suppressor of rainfall
IMD — Key Facts:
- Under: Ministry of Earth Sciences
- HQ: New Delhi (Mausam Bhawan)
- Established: 1875
- National Weather Forecasting Centre (NWFC): 24×7 operational centre
Ahmedabad Heat Action Plan:
- India’s first and model city-level HAP; established 2013
- Partners: AMC (Ahmedabad Municipal Corporation) + IIPH Gandhinagar (Indian Institute of Public Health)
- Serves as the national template for city-level heat response
Urban Heat Island (UHI):
- Effect: Cities are 2–5°C hotter than surrounding rural areas
- Causes: concrete/asphalt surfaces, waste heat from AC, reduced green cover
- Delhi’s green cover: ~20% (below 33% norm)
