If you stepped outside in Vidarbha, parts of Madhya Pradesh, or Marathwada today, you felt it before you checked your phone. A heavy, thick, disorienting wall of heat. The India Meteorological Department (IMD) issued its morning bulletin at 7:51 AM IST on April 16, and the message was clear: the real summer of 2026 has arrived, and it may beat records.
IMD's forecast bulletin for April 16-21 covers multiple weather phenomena simultaneously — a heatwave spreading from Central India toward the northwest, a Western Disturbance arriving tonight over the Himalayas, active rainfall in the northeast, and hot-and-humid conditions across most of the coast. All of this against the backdrop of IMD's Long Range Forecast released April 13, which delivered the most significant weather news of this month: India's 2026 Southwest Monsoon is likely to be below normal.
Let's break this down, region by region.
Today and This Week: Heatwave Warnings Across Multiple States
IMD has issued heatwave warnings — the orange-to-red coded alerts that indicate serious health risks — for the following regions:
Central India:
- Vidarbha (Maharashtra): Heatwave very likely from April 15-18
- Madhya Pradesh: Heatwave in isolated areas, April 16-18
- Marathwada: Heatwave conditions, April 16-18
East India and North India:
- Temperatures in Delhi-NCR: Expected to cross 40°C for the first time this season between April 16-18
- Uttar Pradesh and Rajasthan: Could see 42-43°C during this period
- IMD notes a gradual rise of 3-4°C in maximum temperatures across Northwest India during April 16-18
South and Coastal Regions:
- Hot and humid conditions very likely in isolated pockets over coastal Andhra Pradesh and Yanam (April 16-17), coastal Karnataka, Gangetic West Bengal and Odisha (through April 21), coastal Gujarat (April 16-18), Tamil Nadu, Puducherry & Karaikal, and Kerala & Mahe (April 16-19)
- Rayalaseema: Heatwave on April 17-18
In IMD's classification, a heatwave occurs when maximum temperatures are 4.5°C above normal in a plains station that has already crossed 40°C, or when temperatures cross 45°C regardless of the departure. A "red color warning" in IMD terminology means "take action" — not just awareness. It is a direct signal to authorities and hospitals.
What Has Changed From Early April?
The first half of April 2026 was deceptively cool compared to what was expected. Multiple weather systems — including several Western Disturbances over the Himalayas and cyclonic circulations in the Bay of Bengal — kept temperatures in check. Delhi, for instance, recorded what analysts described as its coolest April fortnight in several years during April 1-10.
That buffer is now evaporating rapidly. The gap between the cool start and the incoming heat is described by meteorologists as a "sudden thermal shift" — temperatures rising by approximately 6°C within a short window. This sudden spike is particularly dangerous for outdoor workers, the elderly, pregnant women, and young children, whose ability to regulate body temperature is limited.
IMD data from past years shows that these rapid heat transitions — rather than gradual warming — are when the most serious heatstroke cases emerge, precisely because the body and preparedness systems have not adjusted.
The Western Disturbance: Tonight's Brief Relief
A feeble Western Disturbance is expected to affect the Western Himalayan Region from the night of April 16, 2026. This will bring:
- Thunderstorms with lightning and gusty winds (40-50 kmph) in Jammu-Kashmir-Ladakh-Gilgit-Baltistan-Muzaffarabad
- Thundersqualls with wind speeds reaching 50-60 kmph in Gangetic West Bengal
- Thunderstorms with gusty winds (40-50 kmph) in Sub-Himalayan West Bengal and Sikkim
For the plains, this system provides limited relief. While it may bring dust storms to Rajasthan and scattered evening thunderstorms to the Indo-Gangetic plain, the heatwave conditions in Central and South India remain largely unaffected by this disturbance.
Northeast India continues to receive the best of this week's rainfall, with isolated showers already recorded in Arunachal Pradesh, Nagaland, Manipur, Mizoram, Tripura, Assam, and Meghalaya.
The Big Picture: Below-Normal Monsoon 2026
On April 13, 2026, IMD Director General held a press conference at the Mahika Hall, Ministry of Earth Sciences, New Delhi, to announce the Long Range Forecast for the 2026 Southwest Monsoon.
The headline: India's SW Monsoon 2026 is likely to be below normal.
Specifically, IMD projects seasonal rainfall at approximately 92% of the Long Period Average (LPA) for the June-September period. The LPA, calculated using 1971-2020 data, stands at 87 cm for the season. This puts India's expected monsoon rainfall in the 80-82 cm range, with a plus-or-minus 5% variation. Broadly, rainfall could land anywhere between 90% and 95% of normal.
The culprit, IMD says, is a developing El Niño.
Currently, the Pacific is in a "weak La Niña-like" transitional phase, moving toward ENSO-neutral conditions. However, IMD's Monsoon Mission Climate Forecast System (MMCFS) projects that full El Niño conditions will develop during the Southwest Monsoon season itself. El Niño events — characterized by warming of the central and eastern Pacific Ocean — historically suppress Indian monsoon rainfall. The 2023 El Niño, for instance, led to deficient rainfall in many parts of peninsular India.
IMD will issue an updated forecast in the last week of May, just before the monsoon is expected to arrive over Kerala's coast (historically around June 1-3).
What Below-Normal Monsoon Means for India
A below-normal monsoon is not a drought declaration. But it has cascading implications:
Agriculture: The Kharif crop — rice, pulses, oilseeds, cotton, and sugarcane, sown from June onwards — depends on the southwest monsoon. A 8-10% shortfall in rainfall will affect planting decisions, yield projections, and procurement prices. About 58% of India's agricultural land is rain-fed. IMD's forecast has immediate relevance for crore of farmers.
Food Inflation: Lower Kharif production means tighter supply, which means higher food prices. India is already dealing with elevated food inflation driven partly by vegetable prices and partly by disruptions from the West Asia conflict on import supply chains. A weak monsoon would add another layer.
Water Reservoirs: India's major reservoirs, including those in Vidarbha, Marathwada, Bundelkhand, and parts of Rajasthan, are already at lower-than-average levels following a modest 2025 monsoon. A second consecutive weak monsoon raises drinking water and irrigation concerns.
Economic Impact: The World Bank's revised GDP forecast for India of 6.6% for FY27 already factors in some monsoon risk. If the monsoon performs at the lower end (90% or below), that forecast could see further revision.
Power Sector: Hydroelectric generation, which contributes about 12-13% of India's installed capacity, would be under pressure if reservoirs don't fill adequately.
Heat Action Plans: Are Cities Ready?
In the context of IMD's warnings, India's urban heat action plans — which most state governments have had in place since 2013-15 — are being activated. Key measures typically include:
- Cooling centres and shelters opened in government buildings, railway stations, and dharamshalas
- Mid-day school timings adjusted in affected states
- Health advisories by ASHA and ANM workers at the grassroots level
- Hospitals placed on heatstroke triage alert
- Outdoor construction workers advised to rest between 12 PM and 3 PM
IMD experts and public health professionals have emphasized that even people in indoors environments are not fully safe without adequate hydration and ventilation. In Vidarbha and Marathwada, where power supply can be irregular, the risk is amplified.
Key IMD Alerts Summary — April 16-21
April 16-17: Orange/Red alert — Vidarbha, Marathwada, Coastal AP April 16-18: Orange alert — MP, Coastal Gujarat, NW India temperature rise April 16-19: Hot and humid — TN, Kerala, Coastal Karnataka April 16-21: Hot and humid, heatwave risk — Gangetic WB, Odisha April 17-18: Heatwave — Rayalaseema Tonight (April 16): Western Disturbance arrives over Western Himalayas Northeast: Continued rainfall through the week
