Jump To:

• heat island
  heat island

  noun

  an urban area having a higher average temperature than its rural surroundings owing to the greater absorption, retention, and generation of heat by its buildings, pavements, and human activities.
• heat-island
  heat-island

  noun

  meteorol the mass of air over a large city, characteristically having a slightly higher average temperature than that of the surrounding air

heat island

American  

[heet ahy-luhnd] / ˈhit ˌaɪ lənd /

noun

1. an urban area having a higher average temperature than its rural surroundings owing to the greater absorption, retention, and generation of heat by its buildings, pavements, and human activities.

---

heat-island British  

noun

1. meteorol the mass of air over a large city, characteristically having a slightly higher average temperature than that of the surrounding air

---

Etymology

Origin of heat island

First recorded in 1960–65

Example Sentences

Dehydration and heat stroke can occur when temperatures rise, and urban heat island effects can also help to trap pollution leading to poor air quality.

From BBC • Jun. 28, 2025

Urban green spaces provide shade for city dwellers facing rising temperatures brought on by climate change, but how much relief from the heat island effect do they provide when humidity is factored in?

From Science Daily • Nov. 14, 2024

These risks are exacerbated by the urban heat island effect — in which buildings and concrete absorb and give off more heat from the sun than trees and vegetation.

From Salon • Sep. 3, 2024

Today, they are “rocking and thriving, even in that windy, harsh, heat island of a location.”

From Los Angeles Times • Jun. 14, 2024

The loss of unpaved space in the city could add to the urban heat island effect, absorbing rather than reflecting heat and contributing to higher temperatures than areas with more vegetation.

From Seattle Times • Feb. 24, 2024