India’s cities trap heat, making them hotter than the countryside

India is building skyscrapers and highways at a record pace. But this rapid urban growth has a dangerous side effect: cities are turning into “heat traps.” Scientists define a heat trap as an urban area where concrete, asphalt, and buildings absorb sunlight during the day and release it slowly at night. This makes cities significantly hotter than nearby rural areas. In India, this effect is getting worse. As more people move to cities, construction booms. New buildings replace trees and green spaces. Without shade and moisture from plants, the ground cannot cool down. At the same time, air conditioners and vehicles pump out extra heat. The result? Nighttime temperatures in Indian cities are rising faster than in the countryside. For example, in Delhi, the temperature difference between the city center and outer villages can reach up to 8 degrees Celsius. This makes sleeping difficult and raises the risk of heatstroke for millions of people. Experts warn that the problem will grow. India’s urban population is expected to double by 2050. Unless cities plant more trees and use lighter building materials that reflect heat, the “heat trap” will only tighten.