Almost 76 per cent of Delhi persistently heat-stressed in summers, says new CSE report

• 50 per cent of the city’s population comprises of vulnerable communities: construction workers, homeless, dwellers of informal settlements, gig workers, street vendors – they are hit most severely 
• Report presents a comprehensive action plan for Delhi – can equip the city to respond to extreme heat conditions in a way that can help everyone and the most vulnerable

 Free download of the CSE report

New Delhi, June 2, 2026: “Delhi is in the grip of an escalating urban heat crisis: dangerously high ‘feels-like’ temperatures are causing fatalities, and are projected to result in severe economic losses equivalent to – as a McKinsey analysis says -- up to 4.5 per cent of India’s gross domestic product (GDP)” – says a new report from Centre for Science and Environment (CSE) released here today to mark the Global Heat Action Day. 

According to the report, “geospatial analysis confirms that 75.78 per cent of Delhi’s area is persistently heat-stressed, a condition worsened by the dramatic shrinking of the city’s green cover. Current actions to contain this crisis are proving to be insufficient because of a lack of a targeted resilience strategy for highly vulnerable groups such as construction workers, street vendors and informal settlement dwellers, many of whom reside or work in heat hotspots.” 

Making Delhi Heat-Resilient, as the report is titled, says that in 2025, the ‘feels-like’ temperatures in Delhi reached as high as 52°C, as per the India Meteorological Department (IMD). In 2024, the Union Ministry of Health and Family Welfare had reported 25 heat-related deaths in the city –independent reports put this number at more than 55. 

Speaking on the methodology adapted by the CSE study, Rajneesh Sareen, the Centre’s programme director for sustainable habitat, says: “We began by gathering evidence on the spatial disparity of heat seen in the city. Landsat data was analysed to identify heat spots and spatial changes in the natural heat sinks.A threshold of 45°C Land Surface Temperature (LST) was considered: areas which breached this value repeatedly for more than six years were identified as heat-stressed.” 

The study also identified and pinpointed the locations of vulnerable population groups – the spatial distribution of these groups was overlaid with heat-stressed areas. 

What did the CSE study find

• Widespread heat stress: 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.
• Heat hotspots: 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).
• 56 per cent of Delhi’s wards have more than 75 per cent of their area exposed to recurring heat stress; 17 have their entire area under heat stress – these localities include locations that are dense, low-rise settlements with little to no greenery.
• Loss of natural sinks: The city’s natural defenses are diminishing; green cover has shrunk from 25.36 per cent in 2014 to 14.14 per cent in 2024. Waterbody footprints have reduced from 1.25 per cent to 0.99 per cent in the same period.
• Delhi’s core area cools 3.8°C less than its peri-urban counterparts, causing heat stress to be retained round-the-clock in its dense concrete-heavy neighbourhoods.
• Mitigation opportunity: Cool areas like Lutyen’s Delhi, Civil Lines and Delhi Cantonment have remained below the stress threshold, largely due to low density and 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 – matters.
• The vulnerable: Every vulnerable group is living or working in high heat-stress zones. For example, construction workers face high occupational vulnerability – 92 per cent of construction projects are located in areas where LST has exceeded the 45°C threshold at least once between 2015 and 2024, and 77 per cent are in areas witnessing recurring extreme heat.
• 80 per cent of Delhi’s workforce is employed in the informal sector; 75 per cent of the city’s women workers are in this sector. The economic cost of heat stress is severe: the World Bank says India will lose 34 million jobs due to heat stress-linked productivity decline. 

According to Mitashi Singh, programme manager, sustainable habitat, CSE: “The CSE report’s estimations and observations match what is happening in Delhi currently. On May 25, 2026, Delhi's land surface temperature ranged from 31.59°C to 54.61°C, with a city-wide mean of 43.15°C. The highest surface temperatures -- exceeding 50°Cin many cases -- were observed in the western, north-western and south-western parts of Delhi, particularly in Karala, Mundka, Begumpur, Bawana, Chhawla and Khera.” 

She adds: “Delhi recorded its warmest May night in nearly 14 years on May 25,2026 with 32.4°C. According to the India Meteorological Department (IMD), on May26, maximum temperatures ranged from 43.5°C at Safdarjung and 44.8°C at Ayanagar to 44.6°Cat Ridge, highlighting the widespread intensity of the heat across Delhi.” 

What does the CSE study recommend?

Why is Delhi in this state in summers? 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 and waste from ACs and vehicles. 

Says Sareen: “Delhi’s vulnerable communities, which constitute 50 per cent of the city’s population, 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.” 

He adds: “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 reacheda 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. 

The CSE study proposes a dual-strategy roadmap to address this. It includesimplementing 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 newbuildings 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 mandatorycooling breaks, staggering work timings, developing standard operating procedures, and dedicated fiscal, medical and supportduring extreme heat emergencies. 

See the CSE report (Chapter 7) for a comprehensive Action Plan for Delhi. 

Says Anumita Roychowdhury, CSE’s executive director and the head of its sustainable urbanisation teams: “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 nowbecome vital for cities to make them liveable in climate-risked times.” 

For more information, interviews etc, please contact Sukanya Nair of The CSE Media Resource Centre: sukanya.nair@cseindia.org, 8816818864