Delhi residents are experiencing scorching nights due to the urban heat island effect, with April recording unusually high minimum temperatures. Experts attribute this to concretization, shrinking green spaces, and thermally poor construction materials. This night-time heat is more harmful than daytime temperatures, impacting both health and the economy, increasing energy consumption and reducing productivity.
Source: why is delhi hot: Hot after hours: Why Delhi won’t chill at night anymore – The Economic Times
The Urban Night 