Why are temperatures within a city’s neighbourhoods different?

Subject: Geography

Section: Climate

Urban heat islands or UHIs are metropolitan areas that are significantly warmer than the surrounding rural areas.

Causes of Urban Heat Island Effect

Disappearing green and blue spaces ( Vegetation and water bodies):the loss of tree cover in cities allows much less cooling of the area through evapotranspiration – a combination of evaporation (movement of water to air from surfaces such as soil, water bodies, etc.) and transpiration (movement of water through plant roots into the air via tiny pores in leaves called stomata).
Urban Canyon/ geometric effects :buildings, especially tall ones, provide multiple surfaces that reflect and absorb heat from sunlight. In addition, multiple tall buildings in close proximity to each other also act as barriers to air flow and wind, which block cooling by convection. These two factors together lead to the urban canyon or street canyon effect.
Construction: the dark surfaces and thermal bulk properties of the most abundant materials in cities – asphalt (roads) and concrete (most buildings) – makes them absorb much more heat than surrounding rural areas
Anthropogenic heat generation and air pollution: Anthropogenic heat is produced by vehicles and buildings (through electric devices like fans, computers, refrigerators, and air conditioners), although this is considered to be almost negligible in commercial and residential areas as compared to the other three factors. The high levels of air pollutants in cities, however, especially carbon dioxide and ozone, both of which are greenhouse gases, are thought to contribute significantly to the UHI effect.