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.

According to the data, 92 per cent of construction projects saw land surface temperatures cross the 45 degrees Celsius mark at least once, with 77 per cent located in zones facing recurring extreme heat. Furthermore, 84 per cent of 643 mapped marketplaces, including major mandis, and 80 per cent of 1,066 mapped schools are situated within heat-stressed localities.

The exposure varies across the city's administrative divisions, with 17 wards having their entire area under heat stress. Additionally, 82 wards have more than 90 per cent of their area affected, and 153 out of Delhi’s 272 wards have over 75 per cent of their territory exposed to recurring heat. The report identified 35 wards as having "very high" to "high" cumulative vulnerability, specifically naming areas such as Matiala, Kakraula, Narela, and Chandni Chowk.

To map the human cost, researchers overlaid the locations of vulnerable groups — including children, the elderly, women, construction workers, street vendors, the homeless, and residents of informal settlements — with the heat-stressed zones. The findings indicate that 76 per cent of mapped informal settlements, which house roughly 1.32 million people, are located in heat-stressed neighbourhoods.

This sustained exposure has translated into severe health risks. The report noted that while the Union Ministry of Health and Family Welfare officially reported 25 heat-related deaths in Delhi in 2024, independent reports estimated the toll to be higher, exceeding 55 fatalities. Reported PTI, the crisis has only deepened, with "feels-like" temperatures climbing as high as 52 degrees Celsius in 2025.

A critical factor in the city's inability to cool down is the built environment. Delhi’s capacity to cool down at night dropped by 9 per cent during the decade. The city’s core cools 3.8 degrees Celsius less than peri-urban areas, locking in round-the-clock heat stress within dense, concrete-heavy neighbourhoods. During summer months, land surface temperatures reached as high as 60.77 degrees Celsius at the Indira Gandhi International Airport, as well as in areas with barren stretches and unsown agricultural land.

The report catalogued a vast list of persistently heat-stressed regions, including commercial and transit hubs like Connaught Place inner circle, Karol Bagh, Kashmere Gate ISBT, Bhikaji Cama Place, and Sarai Kale Khan. Industrial hotspots such as Bawana, Narela, Mayapuri, Mundka, Anand Parbat, Mongolpuri, and the Ghazipur industrial area have also emerged as major hotspots, alongside residential neighbourhoods recording land surface temperatures ranging from 44 degrees Celsius to 50 degrees Celsius.

Other heat-stressed locations include the walled city and its extensions, Uttam Nagar, Palam, Dabri, Najafgarh, Kanjhawala, Budh Vihar, Samaypur Badli, Bhalswa, Jahangirpuri, Burari, Shahdara, Bhajanpura, Karawal Nagar, Badarpur, Madanpur Khadar, Tughlaqabad, Sangam Vihar, Mahipalpur, Aya Nagar, AIIMS, RK Puram, Kotla Mubarakpur, and parts of Green Park, Greater Kailash, East of Kailash, and Lajpat Nagar. Notably, newly built and redeveloped infrastructure projects — including Bharat Mandapam, the East Kidwai Nagar housing complex, Netaji Nagar, and the World Trade Centre in Safdarjung — were also identified as heat-stressed.

The escalation of urban heat coincides with a sharp decline in Delhi's natural cooling mechanisms. Between 2014 and 2024, the city's green cover shrank from 25.36 per cent to 14.14 per cent, while the footprint of its water bodies reduced from 1.25 per cent to 0.99 per cent. Compounding the problem, roughly 35 per cent of the remaining green and blue areas are themselves heat-stressed, meaning that simply expanding these spaces is insufficient without also improving their ecological quality.

Conversely, regions like Lutyens' Delhi, Civil Lines, and Delhi Cantonment managed to remain below the heat-stress threshold, largely due to extensive tree cover and shading over paved surfaces. PTI reported that the Yamuna river also offers localized relief, maintaining land surface temperatures close to 33 degrees Celsius along its banks.

"Delhi is in the grip of an escalating urban heat crisis," the report warned. It added that heat-related productivity losses could eventually strip up to 4.5 per cent of India's GDP, amounting to approximately USD 150-250 billion by the end of this decade.

To mitigate these losses, the CSE has called for an immediate heat resilience strategy tailored to vulnerable groups. Recommended interventions include the deployment of thermally efficient roofs, the establishment of public cooling centres, the implementation of climate-responsive urban planning, and the aggressive expansion of high-quality green cover across the capital.

(With inputs from PTI)