What happened

A study on major Indian cities has found rising night-time temperatures, including in Delhi, Mumbai, and Hyderabad. The finding matters because higher minimum temperatures reduce sleep quality and raise heat stress, especially for vulnerable groups.

Why the issue matters

Urban heat, dense construction, and climate change combine to keep cities warmer after sunset. Night-time heat is not only a comfort problem; it can affect health and productivity and can be as harmful as daytime heat for people already at risk.