Almost 76 per cent of Delhi is persistently heat-stressed in summers, says new CSE report
“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),” the report added.
In 2025, the ‘feels-like’ temperatures in Delhi reached as high as 52°C, according to the India Meteorological Department (IMD). In 2024, the Union Ministry of Health and Family Welfare had reported 25 heat-related deaths in the city, which independent reports estimated at more than 55.
“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,” Rajneesh Sareen, CSE’s programme director for sustainable habitat, said, according to a statement by CSE.
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.”