India is experiencing severe heatwave conditions with both daytime and night temperatures markedly above normal by more than 5.1°C across central and northwestern regions. According to the India Meteorological Department, temperatures in Delhi are expected to touch 45°C this week, with heatwave conditions extending for almost a week. Latest IMD forecasts show 45°C in Delhi and 46°C in Nagpur on 18 May, with isolated pockets near 48°C in some areas. This represents the second heatwave this summer, following earlier conditions in mid- to late-April that resulted in reported fatalities. The current crisis is particularly severe as current IMD warnings show heatwave conditions across Rajasthan, Uttar Pradesh, Madhya Pradesh, Vidarbha, Chhattisgarh, Gujarat and Maharashtra, with temperatures reaching 46°C in Amravati and Wardha, making them among India's hottest locations. As SPR India reports, what we're experiencing is no longer just "summer." It's a growing public health, economic, and equity crisis reshaping how we live and work.
A new study has exposed a critical thermal challenge facing urban India, with homes failing to cool effectively even after sunset. According to the report titled Nighttime Thermal Stress in Low- and Middle-Income Housing in India, nighttime indoor temperatures largely remained between 31.2°C and 32°C, while indoor temperatures frequently crossed 32°C for prolonged periods. Some households recorded nearly 5,700–5,800 hours above the 32-degree mark, equivalent to roughly eight months of continuous exposure to elevated indoor temperatures. The crisis is compounded by India's weather agency revising heatwave definitions, as current criteria based on temperature thresholds increasingly miss dangerous heat conditions caused by high humidity.
The study, which examined 50 residential units in Chennai between October 2025 and April 2026, found that indoor spaces showed limited cooling even after sunset, with most nighttime observations continuing between 32°C and 35.5°C. Researchers noted that the absence of a pronounced leftward shift in the distribution indicates that indoor spaces fail to cool effectively after sunset, with sustained indoor heat exposure having implications for occupant comfort, sleep quality, and long-term health outcomes. The monitoring period did not include peak summer months, suggesting the findings may represent conservative estimates of annual indoor heat exposure. Current IMD warnings show heatwave conditions likely over east Rajasthan and adjoining central India, parts of UP, Haryana, Delhi, Punjab, eastern Gujarat and pockets of Maharashtra over the next four to five days. As SPR India emphasizes, while India has made important strides through Heat Action Plans and early warning systems, gaps remain, especially for those most at risk, highlighting the urgent need for smarter policies, better urban design, and stronger protections for vulnerable communities.
The persistence of indoor heat was attributed to reinforced cement concrete (RCC) structures commonly used in urban housing. According to the report, concrete roofs and walls absorb heat during the day and gradually release it through the night, leading to continued exposure to elevated indoor temperatures even after outdoor temperatures begin to decline. Researchers also found that humidity compounded discomfort, with relative humidity levels across monitored households remaining between 76% and 77% on average, reducing the body's ability to cool itself effectively and worsening perceived heat stress during nighttime hours. The IMD warns that warm night conditions are becoming increasingly common, especially in densely populated urban areas where concrete traps heat and homes often lack cooling systems.
The findings revealed significant health and comfort impacts on residents. During daytime periods, around 45% of indoor conditions were categorised as 'Hot', while another 20% were classified as 'Very Hot'. Residents surveyed frequently reported disturbed sleep, fatigue, and persistent discomfort during the night. The study also highlighted unequal access to cooling systems, with high-income households having access to air conditioners while low-income households relied largely on ceiling fans, with no access to active cooling systems such as ACs or air coolers. However, researchers noted that structural characteristics of buildings played a larger role in shaping indoor heat exposure than household income or occupancy levels. The IMD has explicitly warned of 'high health concern' for vulnerable populations and advised people to avoid prolonged exposure to sunlight.
Despite the mounting heatwave challenges, governance failures are significantly worsening their impacts. As reported by TheWire.in, the Indian government does not recognise a heatwave as a national disaster, with heat deaths still drastically undercounted. The focus remains on more visible short-term actions such as putting up cooling stations rather than crucial long-term actions. Additionally, long-term actions being implemented – such as tree planting – are often not targeted at the right people or places, and therefore do not reach the communities that are most vulnerable to high heat risks. These governance gaps, combined with the structural challenges of urban housing, create a perfect storm for the current heatwave crisis affecting millions across India. As SPR India emphasizes, while India has made important strides through Heat Action Plans and early warning systems, gaps remain, especially for those most at risk, highlighting the urgent need for smarter policies, better urban design, and stronger protections for vulnerable communities.
