What is the conditIon that causes increased temperatures in a city called?

The condition that causes increased temperatures in a city is known as the "urban heat island" effect. This phenomenon occurs when urban areas experience higher temperatures than their rural surroundings due to human activities, modifications of land surfaces, and the concentration of buildings and infrastructure that absorb and retain heat. Factors such as reduced vegetation, increased surface materials like asphalt, and waste heat from vehicles and buildings contribute to this effect.