Living With the Heat: Impact and Building Future Resilience

New Delhi, Gurgaon, Kanpur, Prayagraj, Nagpur, Yavatmal, Kota, Bikaner, Gwalior, and Raipur – 10 cities from six different states – Haryana, Uttar Pradesh, Rajasthan, Madhya Pradesh, Maharashtra and Chhattisgarh – found themselves besides 40 other Indian cities on a ‘Hot List’ compiled by AQI, the air quality monitoring platform, on April 27, 2026. It was a list of the top 50 hottest cities in the world, all of which were from India (Figure 1). There were no cities from the Middle East or sub-Saharan Africa or Australia on the list – regions we traditionally associate with high temperatures. Average maximum temperature across these 50 cities was around 44.7 °C with the lowest maximum temperature reported as 41.9°C in Solapur, Maharashtra. At the time of writing this, major parts of northwest, central and peninsular India including Delhi NCR are facing normal to severe heat waves with maximum temperatures staying between 43 – 45 °C and breaching 47 °C in Vidarbha region, Maharashtra. Such spells of extreme heat are not new in India, and it is how the months of May and June have always been identified with when schools close for annual summer holidays. What is relatively new is how these extreme heat events are now arriving early in April and even late March, and the increasing frequency and duration of these events.

Fig 1: The world’s 50 hottest cities as of 27 April 2026, all located in India.  ( Data Source: AQI); visualization prepared by Sankala Foundation.

Increase in Extreme Heat: A new normal

A heat wave as per IMD is defined as when the normal maximum temperature is 40 °C or higher in the plains or 30 °C or more in hilly regions; the temperature varies by 4.5 °C – 6.4 °C more than normal or 6.4 °C above the normal in case of severe heatwave. A normal temperature of 45 °C and above, is also considered a heatwave, regardless of variations from the average temperature. According to the Intergovernmental Panel on Climate Change (IPCC), the frequency, duration, and severity of heatwaves are only going to rise in the future due to global warming induced by climate change. Studies by IMD show that from 1961 to 2020, the frequency and duration of heatwaves have been increasing in India (Fig.2). Other studies have shown that during 1961-2013, the frequency, average duration and maximum duration of heatwaves over northwest India exhibited a decadal increase of 0.23, 1.3 days and 0.76 days, respectively (Srivastava et al.). The total number of heat wave days experienced across different regions in India with its cyclical variations has been clearly on an upward trend since 2011 (Fig.3). A Lancet study reveals that in 2024, people in India faced an average of 366 more hours of heat stress compared to 1990-99.
Fig.2: Frequency of heat wave events (1961-2020)
Average duration of heat wave events (1961-2020)
Fig.3: Cumulative heat wave days across India over the last 15 years (Source: MoES)
Urban India is heating up faster than the rest of the country due to low tree cover and high density of concrete, asphalt, and glass in the built environment which creates urban heat islands that absorb daytime heat and slowly radiate it back in the night. Tier 1 and Tier 2 cities with population over 10 lakhs experienced an increase in warmer nights during 2012-22 as compared to 1982-2011. Cities like Mumbai and Bangalore experienced 15 and 11 additional warmer nights, respectively in the last decade (CEEW).

The Hidden Costs of Heat Stress: Public Health, Economy and Livelihoods

Heat waves are often described as a silent killer and have a direct impact on public health and a nation’s economy. They have severe effects on physiological well-being of humans as it affects the human body’s ability to regulate temperature which could lead to cramps, exhaustion, and heat strokes. Cardiovascular, respiratory, renal and cerebral diseases aggravate further in extreme heat. It also exposes social inequities as heat waves disproportionately affect the outdoor workers, marginalised and economically weaker sections of the population due their lack of adequate shelter and resources to combat such events. Agricultural and construction labourers, sanitation workers, and the vast network of delivery agents who deliver urban India’s 10-minute doorstep conveniences of groceries, food, and parcels are most vulnerable to ill effects of exposure to extreme heat. Between 1992 and 2015, more than 24,000 deaths were reported to be due to heat waves across India (NDMA). Between 2019 and 2023, 3,712 deaths were reported to be due to heat and sun strokes (National Crime Records Bureau (NCRB)).
Fig.4: The Economic Cost of Heat Stress (Source: Lancet, ILO)

The increase in heat stress is not limited to India but is a global phenomenon. The World Meteorological Organization in its report State of the Global Climate 2025, stated that the 2015-2025 were the hottest 11 years till date. At around 1.43 °C above the 1850-1900 average temperature, 2025 was the second hottest year recorded. This implies more extreme weather events such as intense heat, wildfires, droughts, floods, and cyclones, continued warming of oceans and decreasing ice and glacier coverage in the Arctic and Antarctica. There has been an estimated 63% increase in heat related deaths worldwide since the 1990s with an average of over 5.4 lakh people dying every year.

Fig.5 Global temperature variations in 2025 compared to average temperature during 1991-2020 (Source: WMO)
Increasing heat also threatens water and food security and stresses energy resources. Surface water bodies dry up, and groundwater tables are depleted due to over extraction for drinking and agriculture.
Fig. 6 Heat related mortalities have increased by 63% globally during 1990-2020 (Source: Lancet)
Maharashtra had 10 of the hottest cities reported by AQI in April – all from the Vidarbha region which faces consistent agricultural stress and farmer suicides every year. Extreme heat also increases the demand for electricity with India’s peak power demand hitting a record 256 GW on April 25 this year surpassing the earlier reported peak of 249.8 GW in FY 24-25. As per CEA, this peak demand is expected to grow at 5.58% annually over the next decade, reaching 459 GW in 2035-36. High power demand leads to power outages in many areas which can aggravate the stress for vulnerable populations and even disrupt essential services like water supply and transportation.

Adapting to the rise in heat stress

Extremely hot summers are a normal that we have to adapt our daily lives to and take measures accordingly to protect the children, elderly, pregnant women and others. Adaptation would require policy and governance measures for protection of public health and workers safety and integrating blue-green infrastructure and climate responsive strategies in urban planning.
As countries across the world continue to delay their transition from their fossil fuel powered economies, every new summer will bring headlines of new temperature and electricity demand records being broken. Heat stress will continue to stress public health, food security, livelihood security, water security, and overall economic productivity. Instead of reacting to each heatwave as an emergency, our heat action plans will need to be adapted to the changing climate by not just issuing advisories but also look to redesign our cities, work, and public spaces to be heat resilient by incorporating nature based and less energy intensive solutions.

References

  1. https://edition.cnn.com/2026/05/11/climate/50-hottest-cities-aqi-india-heatwave
  2. https://www.nature.com/articles/srep26153
  3. https://www.bbc.com/news/articles/c5yp8r4ryvmo
  4. https://www.downtoearth.org.in/energy/decoding-indias-record-256-gw-power-peak-demand-dispatch-and-dilemmas
  5. https://timesofindia.indiatimes.com/city/pune/pune-district-administration-issues-heatwave-advisory-directs-firms-to-provide-fans-rest-areas-for-workers/articleshow/131076858.cms
  6. Prabhu, Shravan, Keerthana Anthikat Sukesh, Srishti Mandal, Divyanshu Sharma, and Vishwas Chitale. 2025. How Extreme Heat is Impacting India: Assessing District-level Heat Risk. New Delhi: Council on Energy, Environment and Water.
  7. Ministry of Earth Sciences. Response to Lok Sabha Unstarred Question No. 1546: Deaths Caused Due to Heat Waves.
  8. India Lancet Countdown on Health and Climate Change Data Sheet 2025.
  9. World Meteorological Organisation. State of The Global Climate 2025.

Author

  • Saurabh Datta supports the research and communication efforts in the Water sector at Sankala Foundation. He holds Master’s degrees in chemistry from IIT Roorkee and chemical engineering from the University of Twente, Netherlands. He has diverse experience in programme management, project implementation, research, engineering, and communication in the environment sector.

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