GS1 🌍 Geography

Urban Heat Island (UHI)

/ˈɜːrbən hiːt ˈaɪlənd/

A phenomenon in which urban areas experience significantly higher temperatures (2–5 C or more) than surrounding rural areas, caused by the absorption and re-radiation of heat by concrete, asphalt, and buildings, combined with reduced vegetation cover and waste heat from vehicles, industry, and air conditioning.

Context & Background

UHI intensifies during heatwaves and is a growing public health concern in megacities; mitigation strategies include green roofs, urban forests, cool pavements, and water bodies — studies show that urban greening can reduce UHI by 1–3 C.

UPSC Exam Relevance

GS1 (Geography, Urbanisation). Prelims: definition and causes. Mains: asked in the context of urban climate challenges, heatwave management, and sustainable city planning — often linked to SDG 11 and India's Smart Cities Mission.