Rising nighttime temperatures linked to climate change are increasingly affecting sleep patterns in Indian cities, with Bengaluru and Chennai among the urban areas experiencing significant heat-related sleep loss, according to a new report by Climate Central. The study found that climate change has at least doubled temperature-related sleep loss since the early 1970s across 1,338 major cities worldwide.

The report estimates that the average person globally lost around 56 hours of sleep over the past five years due to extreme heat. More than 10 per cent of this sleep loss was directly connected to climate change, driven largely by rising temperatures caused by human activities such as fossil fuel use and deforestation. Climate Central, an independent group of scientists and communicators, analysed the impact of changing temperatures on sleep using climate attribution research.

India has emerged as one of the countries most affected by climate-related sleep disruption, particularly in southern regions. The study found that cities in southern India recorded annual sleep losses ranging from 78 to 91 hours due to temperature-related factors, with around 8 to 9 hours directly linked to climate change. Researchers noted that densely populated cities are especially vulnerable due to the urban heat island effect, which causes built-up areas to retain heat and remain warmer during nights.

Also Read: DMK Chief M.K. Stalin’s Mother Dayalu Ammal Hospitalised In Chennai

Among Indian states, Tamil Nadu recorded the highest climate change-related sleep loss, with an average of 7.9 additional hours of lost sleep per person annually. Karnataka followed closely with 7.8 hours, while Rajasthan recorded around 7 hours of climate-linked sleep loss. Southern coastal states, including Tamil Nadu, Kerala, and Andhra Pradesh, reported some of the highest overall temperature-related sleep disruptions due to prolonged hot and humid conditions.

Chennai emerged as the most affected major Indian city in terms of overall heat-related sleep loss, with residents losing an average of 93 hours of sleep annually due to high temperatures. Mumbai and Kolkata also recorded significant impacts, with average annual sleep losses of 84 hours and 80 hours respectively. Bengaluru showed the strongest climate change signal among major cities, with around eight additional hours of annual sleep loss attributed to rising temperatures.

Experts warn that reduced sleep caused by increasing nighttime heat could have wider health consequences, including lower productivity, weakened immunity, cardiovascular risks, mental health challenges, and reduced cognitive performance. The report highlighted that vulnerable groups such as elderly people, women, low-income households, and those without access to adequate cooling facilities are likely to face greater risks as temperatures continue to rise.

Also Read: Katchatheevu Sovereignty ‘Settled’ Under International Law, Says Sri Lankan MP In Chennai