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Three-fourths of Delhi faces heat stress as green cover shrinks, CSE study finds

About three-fourth or 75.78 per cent area of the national capital remained heat-stressed for six or more years between 2015 and 2024, according to a latest report by the Centre for Science and Environment (CSE), a research and advocacy organisation based in New Delhi. Majority of construction sites, marketplaces and schools were located in areas experiencing recurring extreme heat, the study found. The report, titled ‘Making Delhi Heat-Resilient: A Roadmap with the Focus on Vulnerable Groups’, said that 98.72 per cent of Delhi's total area crossed the heat-stress threshold at least once during the decade. The report revealed how the extreme heat intensified as the city kept losing its green cover. Delhi's green cover declined from 25.36 per cent in 2014 to 14.14 per cent in 2024, while the footprint of water bodies reduced from 1.25 per cent to 0.99 per cent during the same period.

No relief: 76% of Delhi experienced extreme heat since 2015, new study reveals

Nearly 76% of Delhi's area has faced dangerous levels of heat stress for six or more years between 2015 and 2024, putting millions that reside in the capital city under severe heat stress. The findings, released by the Centre for Science and Environment (CSE), come as Delhi continues to endure another sweltering summer, and illustrate how the city housing over 35 million people has been dealing with extreme heat in recent years, and how the rising temperatures are permeating through everyday lives and reshaping them one day at a time.

Report: 75.78% of Capital’s area heat-stressed for 6 or more yrs

About 75.78 per cent of Delhi’s area remained heat-stressed for six or more years between 2015 and 2024, with a majority of construction sites, marketplaces and schools located in areas experiencing recurring extreme heat, according to a report by the Centre for Science and Environment (CSE). The report, titled “Making Delhi Heat-Resilient: A Roadmap with the Focus on Vulnerable Groups”, said that 98.72 per cent of Delhi’s total area crossed the heat-stress threshold at least once during the decade. According to the study, 92 per cent of construction projects are located in areas where land surface temperatures crossed the 45 degrees Celsius threshold at least once between 2015 and 2024, while 77 per cent are in areas witnessing recurring extreme heat. About 84 per cent of the 643 mapped marketplaces, including major mandis, are situated in areas experiencing recurrent heat stress, while 76 per cent of mapped informal settlements housing nearly 1.32 million people are located in heat-stressed localities, it said. The report also found that 80 per cent of the 1,066 schools mapped in the city are located in heat-stressed areas. It identified 35 wards, including Matiala, Kakraula, Narela and Chandni Chowk, as having “very high” to “high” cumulative vulnerability. According to the report, 153 of Delhi’s 272 wards have more than 75 per cent of their area exposed to recurring heat stress, while 82 wards have more than 90 per cent of their area under heat stress. Seventeen wards have their entire area under heat stress. The report said Delhi faces a deepening crisis from rising temperatures, with “feels-like” temperatures reaching as high as 52 degrees Celsius in 2025. It noted that 25 heat-related deaths were reported in the city in 2024 by the Union Ministry of Health and Family Welfare, while independent reports put the number at more than 55. It added that Delhi is shifting towards a “new and warmer normal”, with increases observed in both annual average maximum and minimum temperatures over the past four decades. Delhi’s ability to cool down at night has reduced by 9 per cent, the report said, adding that the city’s core cools 3.8 degrees Celsius less than its peri-urban counterparts, causing heat stress to be retained round the clock in dense, concrete-heavy neighbourhoods. Areas identified as persistently heat-stressed include the walled city and its extensions, Karol Bagh, Kashmere Gate ISBT and its surroundings, Connaught Place (inner circle), Uttam Nagar, Palam, Dabri, Najafgarh, Kanjhawala, Budh Vihar, Bawana and Narela. A CSE study found large parts of Delhi facing severe heat stress, with temperatures crossing 60 degree Celsius in some locations. Declining green cover, expanding urbanisation and vulnerable populations have intensified risks, prompting calls for heat-resilient planning and expanded green spaces.

76% of Delhi area heat-stressed for six or more years: Report

About 76 per cent of Delhi area remained heat-stressed for six or more years between 2015 and 2024, with a majority of construction sites, marketplaces and schools located in areas experiencing recurring extreme heat, according to a report by the Centre for Science and Environment (CSE). The report, titled “Making Delhi Heat-Resilient: A Roadmap with the Focus on Vulnerable Groups”, said that 98.72 per cent of Delhi’s total area crossed the heat-stress threshold at least once during the decade.

Satellite data shows Delhi surface temperature hit 60°C

Using satellite-derived land surface temperature data, researchers found temperatures reaching as high as 60.77 degrees Celsius during summer months in locations such as the Indira Gandhi International Airport and other barren or sparsely vegetated stretches. Neighbourhoods such as Bawana Industrial Area, Sultanpur Dabas, Puth Khurd, Anand Parbat Industrial Area, Khera Kalan, Mayapuri, Libaspur, Balli Maran, Mongolpuri Industrial Area, Phase II and Mundka Industrial Area have emerged as heat spots. In addition, several residential areas are recording an LST ranging from 44°C to 50°C. The report, Making Delhi Heat-Resilient: A Roadmap with the Focus on Vulnerable Groups, released by the Centre for Science and Environment (CSE), found that 98.72 per cent of Delhi’s area crossed the heat-stress threshold at least once between 2015 and 2024. The report identifies the walled city and its extensions, Karol Bagh, Kashmere Gate, Connaught Place, Uttam Nagar, Palam, Najafgarh, Budh Vihar, Bawana and Narela, among the areas facing recurring heat stress. According to the report, 75.78 per cent of Delhi’s area is persistently heat- stressed (LST > 45°C for six or more years). Nearly 98.72 per cent of the city’s total area crossed the heat threshold at least once over the decade. The report said that new heat spots include industrial areas (Bawana, Mayapuri and Mundka), high-density low-rise residential colonies, and even newly built complexes (like Bharat Mandapam and East Kidwai Nagar) have emerged. The report also links the growing heat burden directly to the shrinking of Delhi’s natural cooling infrastructure. According to the analysis, the city’s green cover declined from 25.36 per cent of its area in 2014 to just 14.14 per cent in 2024. Water-body footprints also reduced, shrinking from 1.25 per cent to 0.99 per cent during the same period. The report found that Delhi breached its normal mean maximum temperature on 42 out of 50 occasions during summer months between 2015 and 2024, suggesting that the city is gradually shifting towards a “new and warmer normal.” According to data shared by the IMD, the Capital’s average maximum temperature in May was 39.7°C, while the average minimum temperature stood at 25.8°C. According to the report, cool areas like Lutyen’s Delhi, Civil Lines and Delhi Cantonment have remained below the stress threshold, largely due to extensive shading over paved surfaces provided by trees. This points to the crucial role of dense canopy cover. At the same time, 35 per cent of existing green/blue areas are themselves heat-stressed, underscoring that the quality – and not just the quantity – of greens matters. In the north, this is happening mainly in Samaypur Badli, Bhalswa, Jahangirpuri, Burari and Azadpur industrial area. In the east, it is Shahdara, Bhajanpura, Karawal Nagar and Ghazipur industrial area; in the south-east, there is Badarpur, Madanpur Khadar, Okhla industrial area, Tughlaqabad and Sangam Vihar. In the south of Delhi, there are Mahipalpur, Aya Nagar, Bhikaji Cama Place, AIIMS, RK Puram, Kotla Mubarakpur, Sarai Kale Khan, parts of Green Park and Greater Kailash, East of Kailash, and Lajpat Nagar along the Ring Road. Interestingly, the newly built Bharat Mandapam and the redeveloped East Kidwai Nagar housing complex, as well as the World Trade Centre in Safdarjung and Netaji Nagar, are equally heat-stressed. One of the report’s most concerning findings is that Delhi’s ability to cool itself during the night is declining. The report highlights how rising temperatures are disproportionately affecting vulnerable populations. Nearly 80 per cent of Delhi’s workforce is employed in the informal sector, where workers often spend long hours outdoors with limited access to cooling, drinking water or shade.

Extreme Heat Risk Grips 76 Percent of Delhi, Schools and Markets Worst Hit: CSE Study

Urban centers in Delhi are trapping heat around the clock, leaving core city areas nearly four degrees Celsius warmer than outer zones at night. A comprehensive report by the Centre for Science and Environment reveals that the national capital has lost nine percent of its natural capacity to cool down after sunset. This night cooling deficit stems from a massive ecological decline over the past decade. The city saw its total green cover plummet from twenty-five point thirty-six percent in 2014 to just fourteen point fourteen percent by 2024, leaving concrete infrastructure exposed to soaring temperatures. Consequently, nearly seventy-six percent of Delhi experienced severe, persistent heat for six or more years between 2015 and 2024. The data shows that almost ninety-eight point seventy-two percent of the capital area breached the extreme heat threshold at least once during this ten-year window. The crisis directly impacts public infrastructure, placing eighty percent of surveyed schools and eighty-four percent of major commercial markets within high-risk zones. Unauthorized colonies housing over thirteen lakh people also sit in these chronically overheated pockets, while industrial areas like Mundka have become permanent heat hotspots. The human cost of this changing climate remains high. While official figures counted twenty-five heat-related fatalities in 2024, independent investigations tracked over fifty-five deaths, highlighting the urgent need for heat-resilient urban planning.

Delhi Heat Stress Report: 76% Area Facing Extreme Heat Crisis

A staggering 76 per cent of Delhi’s area experienced persistent heat stress for six or more years between 2015 and 2024, leaving the vast majority of the capital’s schools, marketplaces, and construction sites vulnerable to recurring extreme temperatures. According to PTI, a new report by the Centre for Science and Environment (CSE) reveals that nearly the entire city — 98.72 per cent — breached the heat-stress threshold at least once over the last decade. The report, titled "Making Delhi Heat-Resilient: A Roadmap with the Focus on Vulnerable Groups", warns that the capital is transitioning into a "new and warmer normal" due to a four-decade climb in both annual average maximum and minimum temperatures. This crisis is compounded by a severe drop in night-time cooling and a rapid depletion of the city's green cover and water bodies, threatening to trigger massive productivity losses. The CSE study, which analysed Landsat satellite data to track areas where land surface temperatures repeatedly exceeded 45 degrees Celsius, highlights an overlapping crisis of infrastructure and vulnerability.

India's solar boom eases daytime demand, but night shortages persist

“The bottleneck on the other side is coal,” said Binit Das from the Centre for Science and Environment. “India faces steep evening ramp requirements of about 60 GW, while national ramping needs reach up to 500 MW per minute on some days. Coal plants, physically constrained below 55 per cent load, simply cannot flex fast enough to follow this curve. Rising night-time temperatures are pushing cooling demand higher precisely when solar generation drops to zero.” At first, India’s record electricity demand this summer appeared to signal a renewable energy success story. On April 25, when peak demand touched 256 Gw, renewables met nearly 30 per cent of the requirement, including solar at 22 per cent, according to Grid India data. But the strain emerged after sunset. At 10.39 pm, the grid recorded a power shortfall of 4.2 Gw. Almost a month later, the pattern was repeated. On May 21, India’s electricity demand climbed further to a record 270.8 Gw. While daytime shortages remained negligible, the grid again reported a sharp rise in shortages during non-solar hours later in the night. At 10.45 pm, the shortage rose to 2.5 Gw. The numbers point to a limitation in India’s energy transition story. The system is becoming increasingly capable of handling daytime demand with solar power, but it is struggling during evening peak hours, when solar generation collapses. The challenge is no longer only about adding renewable capacity. It is about storing daytime solar power and making it available when consumers need it most. Why solar power alone is not enough Solar panels generate electricity only when sunlight is available, while household consumption typically rises after sunset. A rooftop solar home without a battery can use solar electricity during the day but still depend on the grid at night. Similarly, utility-scale solar plants without storage cannot independently meet evening peak demand. The missing link is the ability to store excess daytime electricity and dispatch it later through batteries, pumped hydro systems or other storage technologies. The mismatch is already visible in India’s electricity markets and grid operations. On May 3, electricity prices on India’s main power exchange fell to ₹1.85 a unit by 8 am and kept falling as solar plants offered nearly six times more power than the grid could absorb. By evening, prices climbed back to ₹4-5 a unit as demand rose after sunset. “The bottleneck on the other side is coal,” said Binit Das from the Centre for Science and Environment. “India faces steep evening ramp requirements of about 60 GW, while national ramping needs reach up to 500 MW per minute on some days. Coal plants, physically constrained below 55 per cent load, simply cannot flex fast enough to follow this curve. Rising night-time temperatures are pushing cooling demand higher precisely when solar generation drops to zero.” As solar capacity rises, grid operators are being forced to manage two opposing pressures: excess renewable generation during the day and supply stress in the evening. Where the storage gap is coming from India still lacks enough battery and pumped hydro storage capacity to shift large volumes of daytime renewable energy into evening hours. According to estimates by the Central Electricity Authority, India requires over 411.4 GWh of battery energy storage capacity by 2031-32 to integrate solar and wind capacity. “Storage will become essential for balancing the grid, shifting excess daytime generation to peak consumption periods, and improving the reliability of renewable energy,” said Pratik Kamdar, co-founder and chief executive officer of Neuron Energy. The scale of the storage challenge remains large. India has deployed only around 6 Gw of battery storage so far, even as renewable capacity continues to expand rapidly. Vinay Rustagi, chief business officer at Premier Energies, said the grid could earlier absorb solar variability more easily when renewable penetration was lower. But rapid solar expansion has now created “an acute need for storage capacity to provide firm power to consumers.” The shift is also reshaping investment priorities. “India’s renewable energy sector is clearly entering a second phase focused on storage, flexibility and grid integration, rather than just adding solar and wind capacity,” said Somesh Kumar, partner and leader, power and utilities at EY India. What India needs to fix evening power stress The priority now should be building a power system flexible enough to shift electricity across different hours of the day. Storage deployment is a key part of that shift. While battery prices have fallen sharply over the past decade, industry executives say financing, manufacturing scale and policy execution remain bottlenecks. “The next stage will depend on scaling execution, accelerating domestic manufacturing, and creating investment frameworks that support long-term deployment,” Neuron Energy’s Kamdar said. Grid flexibility is another critical issue. India may need a mix of utility-scale batteries, pumped hydro and distributed storage systems as renewable penetration rises. Das pointed to the need for faster rollout of smart meters and time-of-day tariffs, which can encourage consumers to shift some electricity consumption away from evening peak hours. “Without metering, time-sensitive pricing remains theoretical,” he said. Policy and market reforms will also be needed to attract storage investment. EY India’s Kumar said storage projects still require clearer revenue visibility and stronger market mechanisms to scale up deployment. He pointed to time-of-day tariffs, capacity payments for firm power supply, ancillary services markets, viability gap funding and concessional financing as key enablers. He added that regulatory recognition of storage as a distinct asset class and clearer procurement frameworks for utilities would become increasingly important as India moves towards firm and dispatchable renewable power. The next phase of solar is about night India’s solar story has entered its next phase. The first phase was about making solar cheap and scaling capacity. The next will be about making solar available when consumers need it most. For households, the promise of solar will not be fully realised at noon, when generation is abundant, but after sunset, when the grid is under the most pressure. “India has spent 15 years installing panels. The next 10 will be decided by what it builds around them. The grid doesn't need more solar. It needs more solar hours,” said Das.

Heatwaves Turn Deadly: Why Millions of Animals Have Absolutely Nowhere to Hide

According to an analysis by the Centre for Science and Environment (CSE), extreme weather events killed approximately 77,189 animals across India between January and November 2025. While this figure includes deaths from floods, storms, lightning, and heatwaves. Heatwaves Turns Deadly: Why Millions of Animals Have Absolutely Nowhere to Hide In past few years India’s heat has been increasing on an alarming rate. During 2025 we witnessed heavy heat waves and a lot of people lost their lives due to thin butt in 2026 the heat is wors due to which humans are suffering, but there are lots of other living beings who are suffering in silence. Animals are holding on for their lives as temperatures crossing 46°C in several states and touching nearly 47°C in parts of Maharashtra, animals are increasingly facing dehydration, heatstroke, starvation, and habitat loss. What appears to be an uncomfortable summer for humans can become a death sentence for creatures that cannot seek shelter. Birds, Dogs, Cats, cattle etc are in grave danger as heatwaves in major states reaching newest highs. India’s States have ranked highest in world for having hottest summer. Here are some states with highest heat: Rajasthan 45–47°C Uttar Pradesh 44–48°C Maharashtra 42–46°C Gujarat 42–45°C Telangana 40–44°C Experts warn that rising temperatures are becoming one of the biggest threats to animal survival. In 2026, reports from heatwave-hit states such as Telangana and Andhra Pradesh documented hundreds of bat deaths and livestock losses due to extreme heat, although no official nationwide animal death count has yet been released. The scale of the problem is alarming. According to an analysis by the Centre for Science and Environment (CSE), extreme weather events killed approximately 77,189 animals across India between January and November 2025. While this figure includes deaths from floods, storms, lightning, and heatwaves. While people can go indoors, switch on fans, or drink cold water, animals have no escape from India's extreme heat. Across cities, villages, forests, wetlands, and farmlands, the 2025 and 2026 heatwaves have become a growing crisis for wildlife, livestock, and street animals. A Crisis Hidden in Plain Sight Unlike human deaths, animal deaths from heatwaves often go undocumented. Stray dogs collapse on scorching roads, birds fall from the sky due to dehydration, cattle suffer heat stress, and fish die in shrinking lakes and ponds. Many deaths occur in remote forests, wetlands, and rural areas where there is little monitoring or reporting. As heatwaves become longer and more intense, animals are being pushed beyond their biological limits. Water sources dry up, vegetation withers, and food becomes scarce. The result is a silent emergency unfolding across ecosystems. Wildlife Under Threat Wild animals are among the hardest hit. Forests and grasslands that normally provide food and water become hostile environments during prolonged heatwaves. Deer, monkeys, wild boars, birds, reptiles, and countless smaller species are forced to travel farther in search of water, increasing exhaustion and mortality. hundreds of fish died In several regions of India during 2026, Rajasthan, Gujarat, Maharashtra, Telangana, and Uttar Pradesh were among the worst-hit states where temperatures crossed 45–48°C. In Delhi’s Sanjay Lake, hundreds of fish died after the lake partially dried up and oxygen levels dropped dangerously low. In Chhattisgarh and Uttar Pradesh, hundreds of bats died during extreme heat, while rescue groups treated dehydrated birds, monkeys, snakes, and other wildlife collapsing from heat exhaustion. The problem extends beyond individual animals. Heatwaves disrupt breeding cycles, migration patterns, and ecosystem balance, creating long-term consequences for biodiversity. Street Animals Have Nowhere to Go For India's millions of stray dogs and cats, summer can be brutal. Unlike pets, street animals cannot access cool shelters, clean drinking water, or medical care. Hot roads and pavements can burn paws, while prolonged exposure to extreme heat can cause dehydration and organ failure. Animal welfare organizations across the country report increases in heat-related distress cases during summer months, with many animals requiring emergency treatment. In crowded urban areas, access to clean water becomes a daily struggle. A simple bowl of water placed outside a home or shop can mean the difference between life and death for a thirsty animal. Livestock and Rural Communities Are Also Suffering Heatwaves are not only affecting wildlife and strays. Farmers across India are reporting losses among cattle, goats, buffaloes, and poultry. High temperatures reduce milk production, weaken animals, increase disease risk, and in severe cases cause death. Livestock deaths represent both an animal welfare issue and an economic burden for rural families that depend on these animals for their livelihoods. As climate change intensifies, experts expect heat stress on livestock to become an increasingly serious challenge. Why Heatwaves Are Becoming More Dangerous Scientists have repeatedly linked the increasing frequency and intensity of heatwaves to climate change. Rising global temperatures make extreme heat events more likely, more severe, and longer lasting. For animals, this means: • Reduced access to water • Loss of habitat and food sources • Increased risk of heatstroke • Greater vulnerability to disease • Disrupted breeding and migration patterns Every additional degree of warming increases the pressure on already vulnerable species. What Can Ordinary People Do? Although the problem is large, small actions can save lives. • Keep bowls of clean water outside homes, offices, and shops. • Place water containers on balconies and rooftops for birds. • Plant and protect trees that provide shade. • Support local animal rescue organizations. • Report distressed wildlife to forest authorities or animal welfare groups. • Avoid disturbing animals seeking shelter during extreme heat. These simple steps can provide immediate relief to animals struggling to survive record-breaking temperatures. The Bottom Line India's heatwave crisis is no longer just a human story. It is also an animal welfare and biodiversity emergency. Tens of thousands of animals were killed by extreme weather events in 2025, while reports from 2026 continue to document wildlife and livestock deaths linked to extreme heat. Most of these deaths happen unnoticed. There are no headlines for a thirsty bird falling from the sky or a stray dog collapsing on a scorching road. Yet together they reveal a harsh reality as temperatures rise, animals are paying a growing price for a warming planet. The next time the temperature crosses 45°C, remember that while humans can find shade, millions of animals cannot. Their survival may depend on the choices we make today.

Delhi nights to turn harsher as city experiences urban heat island effect; CSE report warns of 'cooling inequity'

Delhi has been caught in a vicious cycle of trapped heat, losing its critical capacity to cool down at night and triggering severe health risks for over half its population, a new report by the Centre for Science and Environment (CSE) revealed on Tuesday. On May 25, 2026, the capital recorded a night-time temperature of 32.4°C—its warmest night in 14 years. According to the report, titled 'Making Delhi Heat-Resilient', the city's diurnal cooling (the temperature difference between day and night) shrank by 9 percent over the last decade. While a normal summer night used to drop by 12°C compared to the day, that relief has now dwindled to less than 10°C. "Higher night-time temperatures take a heavy toll on human health," said Mitashi Singh, lead author of the report. "It prevents the body from recovering from daytime heat stress, leading to cardiovascular strain, disrupted sleep, and lasting physiological damage." The crisis highlights a stark "cooling inequity." As wealthier residents retreat into air-conditioned spaces, Delhi’s peak power demand has soared to 8,231 MW. However, functioning ACs release trapped heat back into the atmosphere, worsening the urban heat island effect. The CSE also blames Delhi's concrete density, shrinking green spaces, poor building insulation, and vehicle emissions for trapping daytime heat. Construction workers, gig workers, street vendors, and slum residents make up roughly 50% of Delhi's population. For them, a sleepless, sweltering night directly translates to daytime exhaustion, heat sickness, and lost daily wages. Despite this, current city heat action plans offer virtually no strategies to build resilience for these exposed communities. Rajneesh Sareen, programme director, sustainable habitat, CSE, said, “The vulnerable communities are estimated to form at least 50 per cent of Delhi’s population. They do not have adequate means to adapt to the rising heat and are impacted more severely. They toil through the day to earn their daily bread – this becomes brutal when the nights do not provide any respite either. To add to this, if they fall sick – it means wage losses.” To prevent the capital from becoming unliveable, the report urges a dual-strategy roadmap. It calls for city-wide overhauls, including mandating thermally efficient roofs, recognising heat as a notified disaster, and designing wind-ventilated layouts. Crucially, for the outdoor workforce, it demands immediate protections: mandatory cooling breaks, staggered work hours, and dedicated financial and medical support during heat emergencies. Higher night-time temperature can take a heavier toll on human health, Singh added.

Delhi Lost Nearly Half Its Green Cover In A Decade As Heat Stress Engulfed Almost Entire City: Report

Delhi has lost nearly half of its green cover in the last decade, while heat stress has spread across almost the entire city, according to a new report that paints a stark picture of how rapid urbanisation is making India's capital increasingly difficult to cool. The report, Making Delhi Heat-Resilient: A Roadmap with the Focus on Vulnerable Groups, released by the Centre for Science and Environment (CSE), found that 98.72 per cent of Delhi's area crossed the heat-stress threshold at least once between 2015 and 2024. More alarmingly, over three-fourths of the city, 75.78 per cent of its total area, has remained persistently heat-stressed during the decade. The findings come as Delhi experiences increasingly intense and prolonged summers, with heatwaves becoming more frequent and nighttime temperatures remaining elevated for longer periods. Delhi experienced a month of weather extremes in May, recording its hottest May in two years while also registering its cleanest air quality for the month in nearly five years. According to data shared by Indian Meteorological Department (IMD), the capital's average maximum temperature in May was 39.7°C, while the average minimum temperature stood at 25.8°C. Parts of Delhi Touching 60°C Using satellite-derived land surface temperature data, researchers found temperatures reaching as high as 60.77 degrees Celsius during summer months in locations such as the Indira Gandhi International Airport and other barren or sparsely vegetated stretches. Several industrial clusters, including Bawana, Mayapuri, Anand Parbat, Libaspur and Mundka, have emerged as major heat hotspots. Even residential neighbourhoods across the city are routinely recording land surface temperatures between 44°C and 50°C. The report identifies the walled city and its extensions, Karol Bagh, Kashmere Gate, Connaught Place, Uttam Nagar, Palam, Najafgarh, Budh Vihar, Bawana and Narela among the areas facing recurring heat stress. "What is building up the heat stress is unplanned self-constructed housing and buildings," the report notes, highlighting the role of dense urban development, concrete surfaces and shrinking natural landscapes. Delhi Is Losing Its Ability To Cool Down One of the report's most concerning findings is that Delhi's ability to cool itself during the night is declining. According to CSE's analysis, the city's diurnal cooling capacity, the ability to release heat accumulated during the day, has reduced by 9 per cent. The urban core now cools 3.8°C less than peri-urban areas. This means residents are increasingly facing warmer nights in addition to hotter days. The report found that Delhi breached its normal mean maximum temperature on 42 out of 50 occasions during summer months between 2015 and 2024, suggesting that the city is gradually shifting towards a "new and warmer normal." Warmer nights are also driving greater dependence on air-conditioners, creating what researchers describe as a dangerous feedback loop. As more air-conditioners operate, they release waste heat into the surrounding environment, further raising ambient temperatures and increasing electricity demand.

दिल्ली का कूलिंग सिस्टम खत्म! रात और दिन की गर्मी को लेकर ये रिपोर्ट डराने वाली

सेंटर फॉर साइंस एंड एनवायरनमेंट (CSE) की बेहद चिंताजनक रिपोर्ट के अनुसार दिल्ली अब गर्मियों के दौरान रात के समय खुद को ठंडा करने की अपनी प्राकृतिक क्षमता को तेजी से खो रही है. 25 मई 2026 को दिल्ली ने पिछले 14 वर्षों में अपनी सबसे गर्म रात दर्ज की, जिसने शहरी जलवायु परिवर्तन के एक नए और भयावह संकट को उजागर कर दिया है. हर साल जब दिल्ली भीषण गर्मी की चपेट में आती है, तो दिन के समय झुलसाने वाली धूप के बाद लोग रात में थोड़ी राहत की उम्मीद करते हैं, लेकिन अब दिल्ली की रातें भी लोगों को कोई राहत नहीं दे रही हैं. यह स्थिति न केवल सामान्य जनजीवन को प्रभावित कर रही है, बल्कि शहर के बुनियादी ढांचे, पर्यावरण और सार्वजनिक स्वास्थ्य पर भी गंभीर संकट खड़ा कर रही है. रिपोर्ट बताती है कि दिन और रात के तापमान के बीच का यह कम होता अंतर दिल्ली को ऐसे अर्बन हीट आइलैंड में बदल रहा है, जहां से गर्मी बाहर नहीं निकल पा रही है. भारतीय मौसम विज्ञान विभाग (IMD) के अनुसार एक रात को गर्म रात तब घोषित किया जाता है, जब दिन का अधिकतम तापमान 40 डिग्री सेल्सियस से ऊपर बना रहे और रात का न्यूनतम तापमान सामान्य से 4.5 डिग्री सेल्सियस से लेकर 6.4 डिग्री सेल्सियस तक अधिक दर्ज किया जाए. 25 मई को दिल्ली में रात का न्यूनतम तापमान आश्चर्यजनक रूप से 32.4 डिग्री सेल्सियस तक पहुंच गया, जिसने इसे पिछले 14 साल का सबसे गर्म रिकॉर्ड बना दिया. सीएसई के सस्टेनेबल हैबिटैट विभाग की प्रोग्राम मैनेजर और इस रिपोर्ट की लेखिका मिताशी सिंह के अनुसार, यह स्थिति तब पैदा हुई जब पूरे मई महीने में दिल्ली का दिन का तापमान लगातार 40 डिग्री सेल्सियस से ऊपर बना रहा. दिनभर की भयंकर गर्मी के बाद जब रात का तापमान भी 32 डिग्री से ऊपर रहने लगे, तो यह इस बात का स्पष्ट संकेत है कि पर्यावरण में गर्मी को सोखने और उसे वापस अंतरिक्ष में भेजने की क्षमता पूरी तरह खत्म हो चुकी है. दिल्ली के गर्म होने के मुख्य कारण: कंक्रीट का जाल और सिकुड़ती हरियाली आखिर दिल्ली ने रात के समय ठंडा होने की अपनी यह अनमोल क्षमता क्यों खो दी? इसके पीछे कई मानव निर्मित और अनियोजित शहरीकरण के कारण जिम्मेदार हैं. दिल्ली का शहरी ढांचा बेहद सघन और कंक्रीट से भरा हो चुका है. शहर में प्राकृतिक रूप से हवा और पानी को सोखने वाले ग्रीन स्पेस (पेड़-पौधे, पार्क) और ब्लू स्पेस (तालाब, झीलें, जल निकाय) लगातार सिकुड़ते जा रहे हैं. दिल्ली की आधुनिक इमारतें ऐसी सामग्रियों से बनाई जा रही हैं जिनमें उचित शेडिंग (धूप से बचाव) और इंसुलेशन (गर्मी रोकने की क्षमता) की भारी कमी है. इसके अलावा, कॉलोनियों और सोसाइटियों के लेआउट इस तरह से तैयार नहीं किए गए हैं जो प्राकृतिक वेंटिलेशन या हवा के क्रॉस-फ्लो को सहारा दे सकें.

सीएसई की रिपोर्ट के अनुसार दिल्ली में रात का तापमान बढ़ा

सेंटर फॉर साइंस एंड एनवायरनमेंट (CSE) की एक रिपोर्ट के हवाले से आजतक ने बताया कि दिल्ली गर्मियों के दौरान रात के समय खुद को ठंडा करने की अपनी प्राकृतिक क्षमता खो रही है. दिल्ली में 25 मई 2026 को पिछले 14 वर्षों में सबसे गर्म रात दर्ज की गई है, जो शहरी जलवायु परिवर्तन के बढ़ते संकट को दर्शाती है. भारतीय मौसम विज्ञान विभाग (IMD) के अनुसार एक रात को तब गर्म रात माना जाता है जब दिन का तापमान 40 डिग्री सेल्सियस से ऊपर हो और रात का तापमान सामान्य से 4.5 से 6.4 डिग्री सेल्सियस अधिक हो. दिल्ली में 25 मई को न्यूनतम तापमान 32.4 डिग्री सेल्सियस दर्ज किया गया था. शहरीकरण और कंक्रीट के बढ़ते जाल के कारण शहर में ग्रीन स्पेस और ब्लू स्पेस लगातार कम हो रहे हैं. आधुनिक इमारतों में वेंटिलेशन और इंसुलेशन की कमी के कारण दिनभर की गर्मी कंक्रीट की दीवारों में फंस जाती है, जिससे रात का तापमान बढ़ता है.

Delhi is losing its capacity to cool down during summer nights, says new CSE report

On May 25, 2026, Delhi recorded its warmest night in 14 years. Every summer, as the city reels under the onslaught of intense heat during the daytime, its nights are no longer offering any relief – says a new report from Centre for Science and Environment (CSE) released in Delhi on Tuesday. Says Mitashi Singh, programme manager, sustainable habitat, CSE and the lead author of the CSE report: “According to the India Meteorological Department (IMD), a ‘warm night’ occurs when the maximum temperature remains above 40°C and the minimum temperature departs from the normal by 4.5°C to 6.4°C. On May 25, the night-time temperature went up to 32.4°C to qualify it as the warmest on record in 14 years. This was when day-time temperatures have ranged above 40°C across the month.” Making Delhi Heat-Resilient, as the CSE report is titled, focuses on Delhi’s vulnerable communities – construction workers, gig workers, street vendors, the homeless and those living in informal settlements, and its women, children and the elderly – and how they are impacted by the heat. Says Rajneesh Sareen, programme director, sustainable habitat, CSE: “These vulnerable communities are estimated to form at least 50 per cent of Delhi’s population. They do not have adequate means to adapt to the rising heat and are impacted more severely (compared to the more well-off residents). They toil through the day to earn their daily bread – this becomes brutal when the nights do not provide any respite either. To add to this, if there is a heat-related disruption in work – if they fall sick – it means wage losses.” In May 2024, CSE had released another study – Delhi: Urban Heat Stress Tracker ( https://www.cseindia.org/urban-heat-stress-tracker-delhi-12193) – which had estimated that the diurnal cooling had reduced by 9 per cent in the city over the decade of 2014-23. Says Singh: “This means if the day-night land surface temperatures in the decade of 2001-10 had a difference of around 12°C, 2023 showed a difference of 9.8°C.” Singh adds: “Higher night-time temperature can take a heavier toll on human health. It does not allow the body to cool down after accumulating heat stress through the day. This can lead to more cardiovascular strain, disrupt sleep cycles, and disable tissue repair: in simple terms – lasting physiological damage.” Sareen points out that “while city heat action plans acknowledge the different vulnerable groups in Delhi, they do not offer any strategies that can increase their resilience. In the absence of such action, Delhi will see more and more people being affected by rising temperatures. The city needs a scientific and systematic response for its vulnerable populations”. The CSE report says that the soaring temperatures are pushing citizens to resort to air-conditioners – Singh points out that Delhi’s peak power demand recently reached a high of 8,231 MW. The rise in AC use strains the energy systems and aggravates the urban heat island effect. A running AC ejects heat into the ambient environment and heats up the air-shed of those who rely on the outdoor environment for cooling. “Essentially, it spurs cooling inequity,” says the report. Why has Delhi lost its ability to cool down in summer nights? The reasons range from its dense built form, shrinking green and blue spaces, buildings that do not have appropriate shading and insulation, layouts that are not designed to support ventilation, and surfaces that trap heat from ACs and vehicles. The CSE study proposes a dual-strategy roadmap to address this. It includes implementing year-round, city-wide actions such as mandating thermally efficient roofs in industrial areas, office complexes, markets and informal settlements; recognising heat as a notified disaster; developing a heat dashboard; implementing climate-appropriate planning and passive design principles in new buildings and in those that need retrofitting; developing public cooling infrastructure; leveraging existing schemes and climate funds for heat management among others. The second strategy includes focused interventions for exposed populations such as enforcing mandatory cooling breaks, staggering work timings, developing standard operating procedures, and dedicated fiscal, medical and support during extreme heat emergencies. Says Sareen: “Addressing heat vulnerability now requires an active heat management approach. Most important is not looking at it as an occasional occurrence but a harsh reality that is going to stay or perhaps even worsen. This has now become vital for cities to make them liveable in climate-risked times.”

50% of Delhi residents extremely vulnerable to heat, action plan falling short, says CSE

Three-fourths of Delhi’s land is constantly heat-stressed, and 50 per cent of the city’s population is vulnerable to the rising temperatures, says a new report by the Centre for Science and Environment, released on 2 June. The CSE report, titled ‘Making Delhi Heat-Resilient: A Roadmap with the Focus on Vulnerable Groups’, studied the impact of heat stress on the city’s residents, existing action plans, and possible strategies to cope. It also said India needs to, first and foremost, recognise heat as a disaster under the Disaster Management Act, 2005, to respond to it like one. “Addressing heat vulnerability now requires an active heat management approach. Most important is not looking at it as an occasional occurrence but a harsh reality that is going to stay or perhaps even worsen,” said Anumita Roychaudhary, Executive Director, CSE, in a press release. At a launch event at Delhi’s India Habitat Centre, Rajneesh Sareen, Programme Director, Sustainable Habitat, CSE, and one of the authors of the study, said most of Delhi’s vulnerable populations — construction workers, street vendors, and informal settlement dwellers — do not have the means to protect themselves from rising temperatures. “They toil through the day to earn their daily bread – this becomes brutal when the nights do not provide any respite either. To add to this, if there is a heat-related disruption in work – if they fall sick – it means wage losses,” said Sareen at the event. On 25 May this year, Delhi saw one of its warmest nights since 2012, with a temperature of 32.4 degrees Celsius. CSE’s report said this is part of a larger trend of warmer days and warmer nights in Delhi. In the last ten years, the report found, Delhi’s temperature departed from its average maximum summer temperature on 42 out of 50 occasions. This increased warming has come with reduced cooling. The city’s ability to cool itself at night and release the heat trapped during the day has reduced by 9 per cent since 2015. “Warmer nights push people to seek relief through air conditioners, which then aggravate the ambient temperatures,” read the report. “While mechanical cooling benefits a few, the burden of added heat is shared by all.” Strategies to help the vulnerable Older heat action plans have fallen short. The report said that though Delhi’s existing Heat Action Plan, compiled in 2024, initiated steps such as early-warning systems and awareness campaigns, it does not lay out ways to build ‘resilience’ among vulnerable groups. The report suggested measures such as declaring heat a disaster in order to use resources from the State Disaster Response Fund, developing dynamic heat dashboards, expanding heat reportage by measuring wet bulb temperatures, and building thermal roofs and cooling centres. For vulnerable groups, recommended measures include developing standard operating procedures for construction work during high-heat conditions, mandating cooling breaks, enforcing staggered work hours for heat-exposed sectors, and improving access to housing, clothing, and food that support thermal comfort. Delhi’s hot spots Using Landsat imagery and data on Delhi’s land area, the study analysed how some regions bear a bigger brunt of heat stress than others. Built-up areas, industrial regions, and dense neighbourhoods such as Uttam Nagar, Najafgarh, Bawana, Connaught Place, Karol Bagh, and Kashmere Gate ISBT are among the city’s ‘hot’ spots. “As Delhi continues to redevelop, it will need to actively find ways to ensure that the new built-up fabric does not add to the entrapment of heat and instead, mitigates it,” said the report. Only around 24 per cent of Delhi’s total area has remained below the heat-stress threshold, defined as land surface temperature (LST) of less than 45 degrees Celsius. This is due either to green-blue infrastructure — such as parks, trees, and water bodies — or built-up areas with enough green cover, such as Lutyens’ Delhi, Civil Lines, and the Delhi Cantonment. “There are some pockets in Delhi that are able to remain cool for most of the summer… including green neighborhoods like Lutyens, Civil Lines,” said the report. “The biggest takeaway here is the enormous role that shading over paved surfaces can play.”