Friday, 11 Jul, 2025
Source: The Print
Heatwaves across India are endangering both lives and livelihoods, as they become more frequent, prolonged, and intense each year. This escalating crisis calls for a coordinated, year-round national response.
On May 19, Delhi experienced a sweltering day. While the temperature touched 40.8°C—usual for this season—the 44% humidity pushed the heat index to 48.5°C. The ongoing heat wave and resulting environmental stress are real concerns. Heatwaves are now occurring more often, lasting longer, and reaching greater extremes each year. With this pattern becoming the norm, there is an urgent need for a coordinated national response.
The India Meteorological Department (IMD) defines heatwaves as periods of abnormally high temperatures relative to what is typically expected in a particular region. As a result, the temperature threshold for declaring a heatwave varies depending on the temperature climatology (historical temperatures) of that region. The severity of heatwaves can be intensified by additional weather conditions such as high humidity, strong winds, and the duration of the heatwave. A heatwave is officially recognised when the maximum temperature reaches 40°C or higher in plains, and 30°C or more in hilly regions.
Climate change has already been associated with various health problems affecting the lungs, brain, and heart. Now, recent research indicates that higher temperatures can seriously threaten maternal health, with extreme heat linked to higher chances of preterm births and serious complications during pregnancy.
A report by Down to Earth reveals that official data grossly underestimates the impact of heatwaves, overlooking indirect deaths like cardiac arrests or kidney failure among at-risk groups. This underreporting reduces public concern and weakens policy responses, worsening the situation for those most affected. India's population of approximately 1.46 billion includes a large proportion of poor workers who endure physical labour in harsh weather conditions to make a living. This group—comprising construction workers, street vendors, gig workers, farm labourers, rickshaw drivers, domestic workers, and others—are the most vulnerable to the growing impacts of extreme climates, with limited resources to cope.
The IMD has predicted an above-average number of heatwave days in May, following sharp weather contrasts in April 2025. The month was the 50th driest April recorded nationwide since 1901, though central and southern India experienced significant rainfall. Western India, particularly Rajasthan and Gujarat, faced the brunt of heatwaves, experiencing 6 to 11 heatwave days, well above the usual 2 to 3. East Madhya Pradesh and Vidarbha recorded 4 to 6 heatwave days, with Maharashtra and surrounding areas seeing slightly fewer than usual.
A new study by the Delhi-based climate and energy think-tank Council on Energy, Environment, and Water (CEEW) reveals that 57% of Indian districts, home to 76% of the country's population, are currently at 'high' to 'very high' heat risk. The study found that 417 out of 734 districts fall under high and very high risk categories, with 151 districts classified as high risk and 266 as very high risk. Additionally, 201 districts were categorised as moderate risk, while 116 districts were classified as low or very low risk. "This does not mean that these districts are free of heat risk, but that it is relatively lesser than that of other districts," Vishwas Chitale, senior programme lead at CEEW, said.
The study identified 10 states/UTs with the highest heat risk: Delhi, Maharashtra, Goa, Kerala, Gujarat, Rajasthan, Tamil Nadu, Andhra Pradesh, Madhya Pradesh, and Uttar Pradesh. Over half of India's districts, home to 76% of the population and contributing ₹280 trillion to the GDP, are at high to very high heat risk. The study shows that while very hot days are rising in India, the increase in unusually warm nights is even greater, posing serious health risks as the body cannot cool down properly at night.
Rising nighttime temperatures are more common in cities due to the urban heat island effect, especially in densely populated districts with Tier-I and Tier-II cities. This highlights the need for a heatwave resilience policy covering immediate and long-term urban planning.
Urban heat can be reduced by adopting simple, cost-effective solutions like cool roofs, reflective pavements, rooftop gardens, and better building designs with ventilation and insulation. These passive cooling methods lower indoor temperatures and reduce energy use. Singapore uses green roofs to manage building heat, while France tracks vulnerable elderly during heatwaves, showing that small design and policy changes can make a big difference.
India urgently needs a comprehensive, year-round heatwave resilience policy. As heat impacts health, productivity, and infrastructure, consistent action across sectors is essential. Treating it as merely a seasonal issue only heightens long-term risks.
