Page "Urban heat island" Paragraph 7

Other causes of a UHI are due to geometric effects.

The tall buildings within many urban areas provide multiple surfaces for the reflection and absorption of sunlight, increasing the efficiency with which urban areas are heated.

This is called the " urban canyon effect ".

Another effect of buildings is the blocking of wind, which also inhibits cooling by convection.

Waste heat from automobiles, air conditioning, industry, and other sources also contributes to the UHI.

High levels of pollution in urban areas can also increase the UHI, as many forms of pollution change the radiative properties of the atmosphere.