India’s ‘Sleepless Capital’? This Coastal City Lost 93 Hours Of Sleep Due To Climate Change, Says Report
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Between 2020 and 2025, the average person globally lost nearly 56 hours of sleep annually due to high nighttime temperatures, with 6 of those hours due to human-led climate change.
Southern India is bearing a particularly heavy burden. Residents in the region are losing between 78 and 91 hours of sleep every year because of warmer nights, with 8 to 9 hours directly attributable to climate change.
Have you been waking up more often in the middle of the night lately? Or finding it harder to fall asleep even after an exhausting day? While stress, screen time and late-night caffeine are often blamed, a new report suggests another, less obvious culprit could be keeping millions of Indians awake: climate change.
Rising nighttime temperatures driven by climate change are silently robbing millions of Indians of much-needed rest, according to a new report by Climate Central. As India grapples with longer summers and more intense heatwaves, warmer nights are emerging as a serious public health concern, disrupting sleep patterns and increasing the risk of chronic diseases.
The analysis of temperature data from 1,338 major cities worldwide, including 107 in India, reveals that climate change has at least doubled heat-related sleep loss since the early 1970s. Between 2020 and 2025, the average person globally lost nearly 56 hours of sleep annually due to high nighttime temperatures, with around six of those hours directly linked to human-caused climate change.
India’s Worst Affected Cities
Southern India is bearing a particularly heavy burden. Residents in the region are losing between 78 and 91 hours of sleep every year because of warmer nights, with 8 to 9 hours directly attributable to climate change.
- Puducherry records the country’s highest annual sleep loss at 92 hours per person.
- Andhra Pradesh follows with 88.6 hours of annual sleep loss.
- Kerala records 88.3 hours annually.
- Tamil Nadu experiences the highest climate change-attributable sleep loss in India, with 7.9 additional hours per person annually.
- Karnataka records 7.8 climate-attributable hours, while Rajasthan records 7.0 hours, despite comparatively lower overall sleep loss.
- Maharashtra, represented by 22 cities in the analysis, records an average of 76.3 hours of annual sleep loss, including 5.8 hours attributable to climate change, indicating widespread heat-related sleep disruption.
- Uttar Pradesh, covering 11 cities, records nearly 69 hours of annual sleep loss, including 4.9 climate change-attributable hours.
- Chennai records the highest overall annual sleep loss at 93 hours.
- Mumbai loses 84 hours annually.
- Kolkata records 80 hours.
Bengaluru residents however lose 8 additional hours of sleep each year directly due to climate change, the highest among Indian cities. These eight hours account for nearly 12% of the city’s total temperature-related sleep loss.
- Hyderabad: Around 7 hours of annual sleep loss are directly attributed to climate change.
- Ahmedabad: Residents lose approximately 6 hours of sleep annually due to climate change.
- Pune: Climate change is linked to 6 hours of sleep loss each year.
- Delhi: People lose an estimated 66 hours of sleep annually due to high temperatures, of which 5 hours are directly attributed to climate change.
Experts explain that the human body naturally cools down at night to facilitate deep, restorative sleep. When nighttime temperatures remain elevated, this process is disrupted, making it harder to fall asleep and stay asleep.
How is Climate Change Affecting Your Sleep?
According to the report, rising temperatures, especially warmer nights, are making it harder for people to achieve restful sleep. Normally, the human body lowers its core temperature before bedtime to help initiate sleep. When overnight temperatures remain unusually high, this natural cooling process becomes less effective, leading to difficulty falling asleep, frequent awakenings and reduced sleep quality.
Increasing humidity can make matters worse by limiting the body’s ability to cool itself through sweating, leaving many people feeling uncomfortable throughout the night.
How Does Poor Sleep Affect Your Health?
Sleep is essential for nearly every system in the body. Regular sleep deprivation has been linked to a higher risk of cardiovascular disease, obesity, type 2 diabetes, weakened immunity and poor mental health.
Chronic sleep deprivation caused by hotter nights is linked to a wide range of health issues, including heart disease, high blood pressure, type 2 diabetes, weakened immunity, anxiety, depression, and reduced cognitive function. Vulnerable groups such as older adults, pregnant women, children, and people with pre-existing conditions are at greater risk.
Even a few nights of inadequate sleep can affect concentration, mood and reaction time, increasing the likelihood of workplace errors and road accidents. Over time, chronic sleep disruption may also contribute to anxiety, depression and cognitive decline.
Tips to Sleep Better During Hot-Humid Weather
While long-term solutions require policy changes, there are practical steps individuals can take:
- Keep your bedroom as cool and well-ventilated as possible.
- Stay hydrated throughout the day, but avoid heavy meals close to bedtime.
- Use light, breathable cotton bedding and sleepwear.
- Avoid intense physical activity immediately before bed.
- Limit caffeine and alcohol in the evening.
- Maintain a consistent sleep schedule, even on weekends.
- Reduce screen time before bed to support the body’s natural sleep cycle.
Climate change is often associated with floods, heatwaves and rising sea levels, but its effects on everyday health are becoming increasingly difficult to ignore.
Chennai, Mumbai, and Kolkata are among the Indian cities most affected by climate-related sleep loss. Chennai residents lost approximately 93 hours of sleep annually, while Mumbai and Kolkata also experienced significant sleep loss.
