Heatwaves in India
Geography
- PYQs3
- Articles3
Background
Heatwaves are periods of abnormally high temperatures, often exceeding normal maximums, posing significant risks. In India, the India Meteorological Department (IMD) defines specific criteria for declaring a heatwave, based on actual maximum temperatures and their departure from normal. These events are primarily meteorological phenomena influenced by atmospheric circulation patterns and local conditions.
Critical for disaster management, public health policy, agricultural planning, and understanding the socio-economic impacts of climate change in India.
- Heatwave (Plains)
- Departure from normal temperature is 4.5°C to 6.4°C, OR actual maximum temperature is 45°C or more.
- Severe Heatwave (Plains)
- Departure from normal temperature is >6.4°C, OR actual maximum temperature is 47°C or more.
- Heatwave (Hilly Regions)
- Departure from normal temperature is 4.5°C to 6.4°C, OR actual maximum temperature is 37°C or more.
- Severe Heatwave (Hilly Regions)
- Departure from normal temperature is >6.4°C, OR actual maximum temperature is 39°C or more.
Facts & tables
Causes of Heatwaves: Natural factors include atmospheric blocking, anticyclonic circulations, and the absence of moisture-laden winds. Anthropogenic factors like climate change contribute to increased frequency, intensity, and duration of heatwaves. Urban heat island effect, due to concrete surfaces and lack of green cover, exacerbates temperatures in cities.
Impacts of Heatwaves: Public health is severely affected, leading to heatstroke, dehydration, heat exhaustion, and increased mortality, especially among vulnerable populations like the elderly, children, and outdoor workers. Agriculture suffers from crop wilting, reduced yields, and livestock stress. Water resources are strained due to increased evaporation and demand. Energy demand surges for cooling, leading to power outages. Economic productivity declines due to reduced outdoor work capacity.
- Nodal Agency
- India Meteorological Department (IMD)
- Primary Season
- Pre-monsoon (April-June)
- Vulnerable Regions
- Indo-Gangetic plains, Central, Western, and Peninsular India
- Health Risks
- Heatstroke, dehydration, heat exhaustion, increased mortality
- Climate Change Link
- Increased frequency, intensity, and duration of heatwaves
- Key Policy Framework
- National Disaster Management Authority (NDMA) Guidelines for Heatwave
- Frequency Increase
- Frequency of heatwave spells in India's Core Heatwave Zone (central, northwestern, eastern coastal regions) has risen by 0.1 days per decade since 1961.
- Duration Increase
- Maximum duration of heatwaves has increased by 0.55 days per decade in the same zone.
| Category | Plains (Departure from Normal) | Hilly Regions (Departure from Normal) |
|---|---|---|
| Heatwave | 4.5°C to 6.4°C | 4.5°C to 6.4°C |
| Severe Heatwave | >6.4°C | >6.4°C |
| Sector | Specific Impacts |
|---|---|
| Public Health | Heatstroke, heat exhaustion, dehydration, increased mortality, stress on healthcare systems. |
| Agriculture | Crop damage, reduced yields, livestock mortality, food security concerns. |
| Water Resources | Increased evaporation, reduced reservoir levels, water scarcity, higher demand. |
| Energy | Surge in electricity demand for cooling, potential power outages, grid instability. |
| Economy | Loss of productivity, impact on outdoor labor, economic slowdown in affected sectors. |
| Type of Strategy | Examples |
|---|---|
| Early Warning Systems | IMD forecasts, color-coded alerts, dissemination through media and local authorities. |
| Public Health Measures | Heat Action Plans (HAPs), cool shelters, access to drinking water, awareness campaigns. |
| Urban Planning | Green infrastructure (parks, trees), cool roofs, reflective surfaces, urban heat island mitigation. |
| Agricultural Adaptation | Drought-resistant crops, efficient irrigation, livestock management practices. |
| Policy & Governance | NDMA guidelines, state-level disaster management plans, inter-agency coordination. |
| Type | Reference |
|---|---|
| Conceptual area | Disaster Management |
| Conceptual area | Climatology |
| Conceptual area | Environmental Issues |
| Conceptual area | Climate Change Impacts |
| Conceptual area | Climate Change & Conventions |
| Conceptual area | Physical & Regional Geography |
| Body | Role |
|---|---|
| India Meteorological Department (IMD) | Forecasts, warns, monitors |
| National Disaster Management Authority (NDMA) | Policy, guidelines, response |
Prelims angle
For UPSC Prelims, questions often focus on the IMD's definition of heatwaves and severe heatwaves, the geographical distribution of affected regions, the primary causes (both natural and anthropogenic), and the immediate health impacts. Knowledge of key government agencies involved in heatwave management (IMD, NDMA) is also crucial. Questions might also test the understanding of the urban heat island effect.
For UPSC Mains, the focus shifts to comprehensive analysis. Candidates are expected to discuss the multi-faceted impacts of heatwaves on public health, agriculture, water resources, and the economy. Disaster management strategies, including early warning systems, mitigation measures, and adaptation policies (e.g., Heat Action Plans), are important. The linkage between heatwaves and climate change, and India's preparedness and policy responses, are frequently examined, requiring a critical and holistic perspective.
- Definition of heatwave and severe heatwave by IMD (temperature thresholds, departure from normal).
- Geographical distribution of heatwave-prone regions across Northwest, Central, East, and Peninsular India.
- Major impacts on human health (heatstroke, dehydration), agriculture (crop loss), and water resources.
- Mitigation and adaptation strategies, including early warning systems and public awareness.
- Link between increasing frequency/intensity of heatwaves and climate change.
| Year | Framing tags |
|---|---|
| 2025 | Statement-based questions, Conceptual understanding |
| 2023 | Multi-statement analysis, Factual recall |
| 2017 | Multi-statement analysis, Conceptual understanding |
Current affairs
Heatwaves are a persistent and growing concern in India, with the IMD regularly issuing warnings for severe conditions across various states. Recent years have seen a noticeable increase in their frequency and intensity, highlighting the urgent need for robust preparedness and adaptation strategies.
The National Disaster Management Authority (NDMA) has issued comprehensive guidelines for the preparation of Heat Action Plans (HAPs) at state and district levels. These plans focus on early warning, public awareness, capacity building of health professionals, and inter-agency coordination.
Timeline
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Disaster Management
Conceptual area
-
Climatology
Conceptual area
-
Environmental Issues
Conceptual area
-
Climate Change Impacts
Conceptual area
-
Prelims 2017
Multi-statement analysis, Conceptual understanding
-
Prelims 2023
Multi-statement analysis, Factual recall
-
Prelims 2025
Statement-based questions, Conceptual understanding
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Severe heatwave conditions likely to prevail over parts of India: IMD
Persistent periods of abnormally high temperatures, often exceeding normal maximums, affecting large parts of India. Characterized by severe heatwave conditions and warm nights, posing significant challenges to public health and various sectors.
-
Concrete fever: On India and heat management
Heatwaves are increasing in frequency and duration in India, driven by climate change, with severe impacts on vulnerable populations and the economy, necessitating robust heat management strategies.
-
Is India getting hotter?
Heatwaves are prolonged periods of extreme heat, defined by IMD criteria, causing severe health and economic impacts in India, often linked to climate change and monsoon variability.
See also
Dashed boxes: related topics without a notes page yet. Tap a solid box to open notes.
Past papers
2017–2025 · 3 questions
In the news
Is India getting hotter?
Heatwaves are prolonged periods of extreme heat, defined by IMD criteria, causing severe health and economic impacts in India, often linked to climate change and monsoon variability.
Severe heatwave conditions likely to prevail over parts of India: IMD
Persistent periods of abnormally high temperatures, often exceeding normal maximums, affecting large parts of India. Characterized by severe heatwave conditions and warm nights, posing significant challenges to public health and various sectors.
Concrete fever: On India and heat management
Heatwaves are increasing in frequency and duration in India, driven by climate change, with severe impacts on vulnerable populations and the economy, necessitating robust heat management strategies.
Try these PYQs
Consider the following statements:
I. Without the atmosphere, temperature would be well below freezing point everywhere on the Earth's surface.
II. Heat absorbed and trapped by the atmosphere maintains our planet's average temperature.
III. Atmosphere's gases, like carbon dioxide, are particularly good at absorbing and trapping radiation.
Which of the statements given above are correct?
Statement I is correct: Without the atmosphere to trap heat, the Earth’s surface temperature would drop to well below freezing, making it too cold to support life as we know it.
In statement 1 though it's an extreme statement but from UPSC CSE point of view it's generally considered true. Statement II is correct: The atmosphere absorbs and retains heat (a natural greenhouse effect), which helps maintain the Earth’s average temperature within a habitable range. Statement III is correct: Gases such as carbon dioxide, methane, and water vapor are particularly effective at absorbing and trapping infrared radiation, helping to warm the planet.
With reference to ‘Indian Ocean Dipole (IOD)’ sometimes mentioned in the news while forecasting Indian monsoon, which of the following statements is/are correct?
1. IOD phenomenon is characterized by a difference in sea surface temperature between tropical Western Indian Ocean and tropical Eastern Pacific Ocean.
2. An IOD phenomenon can influence El Nino’s impact on the monsoon.
Select the correct answer using the code given below:
Statement 1 is Incorrect: The IOD phenomenon is characterised by a difference in sea surface temperature between the tropical Western Indian Ocean and the tropical Eastern Indian Ocean, not the Eastern Pacific Ocean. During a positive IOD, the western Indian Ocean is warmer than the eastern Indian Ocean, and vice versa for a negative IOD. Statement 2 is Correct: The IOD phenomenon can indeed influence El Nio's impact on the Indian monsoon. El Nio itself is a climate pattern in the Pacific Ocean, but it can interact with the IOD. Depending on the phases of both phenomena (positive/negative IOD and El Nino/La Nina), the overall impact on the Indian monsoon rainfall can be amplified or weakened. Hence, option B is the correct answer.
Consider the following statements:
1. Amarkantak Hills are at the confluence of Vindhya and Sahyadri Ranges.
2. Biligirirangan Hills constitute the easternmost part of Satpura Range.
3. Seshachalam Hills Constitute the southernmost part of Western Ghats.
How many of the statements given above the correct?
* Statement 1 is incorrect: Amarkantak is a pilgrim town in Anuppur, Madhya Pradesh. Amarkantak Hills is the meeting point of the Vindhya, Satpura, and Maikal Ranges. It is also the origin of the Narmada, Son, and Johilla Rivers. * Statement 2 is incorrect: The Billigirirangan Hills, also known as BR Hills, are not a part of the Satpura range. It is a hill range situated in south-western Karnataka, at its border with Tamil Nadu (Erode District). The area is called Biligiri Ranganatha Swamy Temple Wildlife Sanctuary or simply BRT Wildlife Sanctuary. * Statement 3 is incorrect: The Seshachalam Hills, also known as Tirumala Hills, are not a part of the Western Ghats. Seshachalam Hills are hilly ranges part of the Eastern Ghats in southern Andhra Pradesh. The Seshachalam hill ranges are predominantly present in Tirupati district of the Rayalaseema region in Andhra Pradesh.