The unseen toll of climate change: Sleep deprivation in India

By Dr. Gurinder Kaur* 

According to a report released in July 2026 by the Climate Central Institute of the United States, rising global average temperatures are now directly affecting human health. Adequate sleep is one of the fundamental pillars of good health, and the report highlights a troubling trend: as average temperatures rise, both daytime and nighttime temperatures are increasing. With rising night temperatures, millions of people across the world are struggling to fall and stay asleep. 

Between 2020 and 2025, sleep loss averaged 56 hours per person per year globally. The institute compiled data from 1,338 cities with populations exceeding 500,000, supplementing it with historical data to produce the report. The findings also reveal that climate-related sleep loss has at least doubled since the early 1970s.

While sleep deprivation linked to rising night temperatures is a global phenomenon, India is bearing the brunt more than any other country. Between 2020 and 2025, Indians lost an average of 63 to 93 hours of sleep annually due to warmer nights. In comparison, residents of Saudi Arabia, Oman, and the United Arab Emirates lost 55 to 87 hours; people in Niger, Nigeria, and Burkina Faso in West Africa lost about 65 hours; and Americans lost only 35 hours per year on average.

This raises a critical question: why is India more affected than other nations, including those in similarly hot regions? The impact of rising night temperatures on sleep depends on a complex interplay of factors—geographical location, forest cover, wetland area, housing structure and construction materials (soil, wood, concrete, glass), economic status, government regulations, and air pollution levels.

Within India itself, the impact is uneven. Urban residents in southern states are more affected than their counterparts in northern urban areas. Among states and union territories, Puducherry tops the list with 92 sleepless hours annually. Tamil Nadu follows closely, with residents losing 7.9 more hours of sleep per year than the national average. Other severely affected states include Andhra Pradesh (88.6 hours), Kerala (88.3 hours), and Gujarat (81.4 hours).

At the city level, the numbers are even more striking. Chennai leads with 93 hours of sleep loss per year, followed by Kochi, Kozhikode, Tiruchirappalli, and Guntur at 90 hours, Visakhapatnam at 87 hours, Mumbai at 84 hours, Delhi at 66 hours, and Srinagar at just 27 hours.

The southern states’ vulnerability can be attributed to both geography and human activity. Many major cities—Chennai, Kochi, Kozhikode, Mumbai—are coastal. While coastal areas traditionally enjoy milder climates, rising global temperatures have warmed ocean waters as well. This has weakened the natural land-sea breeze cycle: the cool sea breeze that once provided daytime relief and the warm land breeze that flowed seaward at night have both slowed. 

Now, warm, moist air from the ocean exacerbates nighttime heat. Compounding this, wetlands and mangrove forests in these coastal zones have been cleared for commercial establishments, hotels, industries, roads, and shopping centres. These human interventions have made nights in these cities not only hotter but also more humid.

In Delhi, the problem is driven by a combination of climate change and severe air pollution. Across the country, the economically weaker sections suffer disproportionately. Lacking access to effective cooling appliances, they rely on broken or outdated fans and coolers, spending sleepless nights in search of relief. The elderly, women, and children are especially vulnerable.

Srinagar, by contrast, fares better due to its hilly terrain, with residents losing only 27 hours of sleep annually. However, it is worth noting that five to six decades ago, summer temperatures in India’s hill regions remained cool enough that refrigerators, fans, and air conditioners were unnecessary. Today, such appliances have become commonplace, a telling sign of warming even in the mountains.

The bottom line is that climate change is no longer confined to natural disasters and their aftermath. It now threatens one of the most basic human needs—sleep. Sleep deprivation first weakens immunity, opening the door to diabetes, obesity, cardiovascular disease, depression, and other serious conditions. It also reduces work capacity, impairs concentration, and makes people more irritable.

To protect Indians from temperature-induced sleep loss, coordinated action by both Union and State governments is urgently needed—on multiple time scales. Public cooling centres should be established for economically disadvantaged communities during hotter nights. Building designs must be adapted to local environmental and geographical conditions, as concrete and glass structures absorb heat during the day and release it slowly at night. 

Forest cover and shade trees should be expanded, and all water bodies and sources must be preserved and rejuvenated. In particular, the southern states—especially those along the Western Ghats, including Gujarat, Maharashtra, Karnataka, Kerala, Tamil Nadu, and Goa—should fully implement the recommendations of the Gadgil Committee to safeguard their populations from both natural disasters and the health impacts of rising night temperatures.

---

*Former Professor, Department of Geography, Punjabi University, Patiala