Delhi’s Ground Is Burning at 60°C — And a Handwritten Diary Is Bearing Witness

ByNibedita Saha

Jul 9, 2026 #Climate Change, #Environment News, #Extreme heat, #Heatwaves, #New Delhi

A thermal camera, a handwritten diary, and the city’s most invisible crisis

We all have heard or told stories about winters afternoons and rainy mornings but our next generation might share their stories about heatwave days as they are becoming more frequent and unbearable.

“We can’t see the heat but we do feel it and it hurts nowadays. But I can’t afford to sit at home. Who will take care of my children? Somedays I get blackouts during afternoons while driving only but I can’t tell this to my family as they will get tense,” said Jitendra Kumar, an auto driver in Delhi.

The thermal camera’s readings seemed almost impossible. On a stretch of Ring Road on a June afternoon, the surface temperature exceeded 60°C. Just a few metres away, beneath a lone tree, it measured only 39°C. Nearly 20 degrees separated the two spots, all because of the shade provided by a single tree.

That temperature gap tells a powerful story about what is happening to Delhi right now.

Over several days this summer, I carried a thermal camera across four parts of the city — Chandni Chowk’s market lanes, the working-class neighbourhood of Sundar Nagri in East Delhi, the wide stretch of Ring Road, and the green avenues of Lutyens’ Delhi. What the camera captured was not just heat. It was inequality, made visible in colour.

The City That Traps Heat

Delhi’s surface temperatures reached 60°C this summer. Not air temperature — the temperature of the ground beneath people’s feet, the walls they lean against, the bus stop benches where they wait.

This is the urban heat island effect in its most brutal form – when a city replaces soil, trees, and water bodies with concrete, asphalt, and glass, it fundamentally changes how heat moves. Natural surfaces absorb sunlight and then release it slowly orcool the air through moisture and shade. Concrete and asphalt do the opposite. They store solar energy throughout the day and radiate it back through the night, turning the entire neighbourhood into slow-release ovens.

In Chandni Chowk, Delhi’s densely packed historic market district, buildings and roads recorded surface temperatures ranging between 55°C and 60°C in exposed areas. By contrast, in Lutyens’ Delhi, broad avenues shaded by mature trees felt almost comfortable in comparison. The difference could not have been clearer. For perhaps the hundredth time, it demonstrated that green cover is not an aesthetic luxury — it is critical survival infrastructure.

A June 2026 report by the Centre for Science and Environment (CSE) found that 75.78% of Delhi’s geographical area is now persistently under heat stress, with surface temperatures exceeding 45°C for more than six years between 2015 and 2024. Over the same decade, the city’s green cover shrank from 25% to just 14%. The relationship is difficult to ignore. As the trees disappeared, the heat intensified. That is not a coincidence. It is the consequence of choices made over time.

The Baseline Is Shifting

For decades, Delhi’s summers followed a harsh but predictable pattern. The heat would build through May and June, reaching punishing highs before the monsoon arrived to break its grip. Crucially, the nights still offered respite. Temperatures would fall after sunset, giving people, buildings, and infrastructure time to cool and recover before the cycle began again the next day.

That rhythm is breaking.

According to data from the India Meteorological Department (IMD), Delhi endured 36 consecutive days of temperatures above 40°C starting on 12th May 2024, with 16 of those days crossing the 45°C mark. Even after sunset, the heat refused to relent. In June 2024, the city recorded its warmest night in at least 14 years, with the minimum temperature settling at 35.2°C—more than 8 degrees above normal.

In 2025, the heat arrived earlier. IMD issued heatwave warnings for Delhi for nine consecutive days in April alone. This year, six heatwave days were recorded in May 2026, with the mercury touching 45.1°C on 19th May.

The bigger shift is in what was once Delhi’s saving grace: the night. A decade ago, Delhi would cool by nearly 15°C after sunset. By 2025, that night-time cooling had dropped to just 8.6°C — a loss of 42%, according to CSE data. During monsoon months, the fall was similarly diminished.

This matters enormously for human health. Sleep is not simply a period of rest; it is a critical time for the body to cool itself and recover. When nighttime temperatures remain above 30°C — as has become increasingly common in Delhi — that cooling process becomes far less effective. The result is that heat stress does not end with the day. It lingers, accumulating over successive days and leaving the body with less opportunity to recover.

No Escape Indoors

For those living in Delhi’s informal settlements, there is no air conditioning and often no cross-ventilation. As I walked through Sundar Nagri; lanes barely wide enough for two people to pass, the walls on both sides are concrete, the roofs made from tin or asbestos, and windows — where they exist, face other walls.

“We live on the first floor but since the room has no ventilation and the rooftop is empty as well—in the afternoon it feels like a tandoor. If we have water,then I take frequent baths just to cool it down–somedays it works and somedays it doesn’t. During heatwaves it becomes almost impossible to do anything,” said Abhishek, a Sundar Nagri resident.

When visiting the Sundar Nagri colony, the thermal camera showed Abhishek’s house’s indoor-facing surfaces radiating heat well into the evening. By 7:30 PM, the walls were still reading above 41°C. The room inside was reading between 40-42°C.

Similarly, Kajal, another resident of this area shared that she goes to her relative’s house because their fan moves faster and they live on ground floor. “I don’t want to stay home, especially in the afternoons but mom tells me not to roam around the neighborhood,so I go to my relatives or friends. The room burns, I can’t explain it in words but it literally burns–I can feel it in my skin. Even if I take baths 10 times–it won’t help and we don’t get regular water supply. It is a nightmare,” said Kajal.

Research increasingly confirms what residents already know. Prolonged heat exposure, especially without any cooling relief, causes not just physical symptoms — dehydration, exhaustion, heat stroke — but significant mental health impact. Anxiety, sleep deprivation, and irritability are documented responses to chronic heat stress. For daily wage workers whose income depends entirely on being physically present and functional, a bad night’s sleep is not just discomfort. It is money lost.

“On a regular day I earn between 600-800 depending on tourist visits but these days I am not even making 300 in a day,” said Savitri Devi, a dry-fruit seller near the Red Fort area. “Because of this deadly heat, even tourists’ are not coming. But I come everyday because I have no other options–this is my livelihood,” she added.

Savitri, who hails from Gujarat came to the national capital looking for better livelihood options. She sits on a road surface on a thin mat and the temperature of that surface was more than 53°C at the time we were interacting.

The Diary That Heat Forced Into Existence

This summer, in the same neighbourhoods where I carried a thermal camera, a different kind of documentation is underway.

Greenpeace India’s Heat Registry or Garmi Khata is what happens when a community decides to become its own witness. It is a handwritten diary, maintained by residents in Delhi’s most heat-exposed neighbourhoods. It is the people–often referred to as numbers when we talk about heat–who are writing, in their own words, what this heat is doing to their lives.

It is the first community-maintained, handwritten climate evidence initiative of its kind in India.

“I cannot sleep the whole night as it is on the fourth floor. The heat stays trapped inside our home throughout the day. By afternoon the rooms feel unbearable, and even after sunset the walls continue to radiate heat. We cannot sleep properly or study comfortably, and cooking becomes exhausting. Every day feels like a struggle to find a cooler place to sit and breathe,” writes Nagma in her Garmi Khata, documenting how she is bearing the heat along with eight family members including five children in a rented settlement in Sundar Nagri. She works on a piece-rate basis, packing toys from home to earn an income. Her husband works in a nearby factory, stitching shirt collars. The family’s children also contribute to the household earnings by helping with tasks such as packing toys and transporting bundles of T-shirts and other materials. Despite everyone’s efforts, the family continues to face significant economic challenges.

Another keeper of “Heat Registry”, a 19-years-old Arshi shared that she recently went unconscious during one of her exams and later a doctor came, gave her glucose after which she was able to write once again.

“The heat is affecting our future as much as our present. Some days I cannot concentrate on studying for my exams because the room is too hot. My brother, who works as a daily wage labourer, often skips work because travelling and working in extreme temperatures becomes impossible. When he misses a day of work, our family loses income. For families like ours, a heatwave is not just about discomfort—it affects education, livelihoods, family relationships, and our ability to live with dignity,”said Arshi, who is studying political science.

One of Arshi’s diary entry reads: (Translated in English)

“There was so much heat but the environment around here did not cool down even at night. Now if you look at it from 8–10 years ago, till February it would be cold and March would still have mild cold — but now that is no longer the case. The weather has become so bad that we can’t even estimate………..but people are somehow surviving the heat—this wind is the only thing keeping us alive.

The roof of my house is made of RCC — it feels warm on top and it doesn’t cool down even by evening, and from another direction the room heats up, we don’t know what to do inside the room. Our kitchen is upstairs and there is no room there…..at night when it’s time to sleep, the fan stops — then sleep gets disturbed…..if rest is not found during the day in the heat — then rest at 8 PM also doesn’t come — no small thing matters — due to heat, mood becomes bad — and due to mood the person loses patience — and then in the house there is Mahabharat (big quarrel)…we all fight….

I asked papa are you not going for work today……he replied in very low voice
“the factory gets very hot…..there’s no fan/AC……… .continued…..”

This is what climate data looks like when it is written from the inside. Not land surface temperatures captured by satellite — though those matter — but the felt reality of a city that has become for millions of people.

What the Camera Showed, and What It Didn’t

The thermal camera is revelatory and limited at the same time. It shows you the 20°C difference a single tree makes on Ring Road. It shows you the heat radiating off a concrete wall in Sundar Nagri at 9 PM. What it cannot show is cumulative damage. The sleep lost over 60 nights. The wages not earned because the body gave out. The anxiety that builds when every summer is worse than the last and there is no plan that reaches your lane.

Delhi is being mapped in many ways this summer — by satellites, by thermal camera, by IMD stations. The Garmi Khata is mapping it differently: handwritten entry by the people who have no choice but to live through it.

The trees on Lutyens’ roads are doing what trees have always done. They are cooling the ground by 20 degrees, cleaning the air, and keeping the street somehow livable and walkable too.

Arshi is studying political science in a room that doesn’t cool until past midnight. Nagma is packing toys by day and searching for sleep by night. Jitendra is driving through blackouts he cannot tell his family about. Savitri is sitting on a 53°C road surface selling dry fruit because she has no other option. And one will find thousands of similar stories on the ground.

These people are not just statistics to quote the death toll in reports, highlighting percentages of people impacted the most by heat—they are real people who are suffering, struggling and fighting every day to cope with this heat.

The thermal camera shows the heat. The Garmi Khatashows what it costs.

The author visited Chandni Chowk, Sundar Nagri, Ring Road, and Lutyens’ Delhi with a thermal camera to document surface temperature variation across the city’s heat landscape. The Heat Registry (Garmi Khata) is an ongoing initiative by Greenpeace India.