Skip to main content
U.S. flag

An official website of the United States government

Here’s how you know

Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

HTTPS

Secure .gov websites use HTTPS
A lock (LockA locked padlock) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

    • Environmental Topics
    • Air
    • Bed Bugs
    • Cancer
    • Chemicals, Toxics, and Pesticide
    • Emergency Response
    • Environmental Information by Location
    • Health
    • Land, Waste, and Cleanup
    • Lead
    • Mold
    • Radon
    • Research
    • Science Topics
    • Water Topics
    • A-Z Topic Index
    • Laws & Regulations
    • By Business Sector
    • By Topic
    • Compliance
    • Enforcement
    • Laws and Executive Orders
    • Regulations
    • Report a Violation
    • Environmental Violations
    • Fraud, Waste or Abuse
    • About EPA
    • Our Mission and What We Do
    • Headquarters Offices
    • Regional Offices
    • Labs and Research Centers
    • Planning, Budget, and Results
    • Organization Chart
    • EPA History

Breadcrumb

  1. Home
  2. Heat Islands

Learn About Heat Island Effects

Heat islands are urbanized areas that experience higher temperatures than outlying areas. Structures such as buildings, roads, and other infrastructure absorb and re-emit the sun’s heat more than natural landscapes such as forests and water bodies. Urban areas, where these structures are highly concentrated and greenery is limited, become “islands” of higher temperatures relative to outlying areas. Daytime temperatures in urban areas are about 1–7°F higher than temperatures in outlying areas and nighttime temperatures are about 2–5°F higher. Learn more about the impacts and how to measure heat islands.

  • What are Heat Islands?

    Smog in the city of Chicago

    Learn about heat island causes, characteristics, impacts, and solutions to reduce them.

    Explore the Causes and Impacts
  • Measuring Heat Islands

    Aerial view of the edge of Central Park

    Find key considerations for assessing local heat island effects.

    Discover Measurement Frameworks

More Information and Resources

  • Guide to Reducing Heat Islands - Find chapters detailing heat island causes, impacts, and cooling strategies.
  • Heat Island Trends - Learn about heat island trends, and the benefits of reducing heat islands. 

Heat Islands

  • Learn About Heat Island Effects​
    • What Are Heat Islands?
    • Measuring Heat Islands
  • Heat Island Reduction Solutions
    • Trees and Vegetation
    • Green Roofs
    • Cool Roofs
    • Cool Pavements
    • Adapting to Heat
    • Smart Growth and Heat Islands
  • Community Heat Island Efforts
    • Community Actions Database
    • Local Heat Stories
  • Guide to Reducing Heat Islands
  • Heat Island Outreach
    • Webinars
    • Cool Your Community Social Media Toolkit
    • Outreach Materials
  • Heat Island Resources
    • Frequent Questions and Resources
    • Related Links
Contact Us About Heat Islands
Contact Us to ask a question, provide feedback, or report a problem.
Last updated on April 2, 2025
  • Assistance
  • Spanish
  • Arabic
  • Chinese (simplified)
  • Chinese (traditional)
  • French
  • Haitian Creole
  • Korean
  • Portuguese
  • Russian
  • Tagalog
  • Vietnamese
United States Environmental Protection Agency

Discover.

  • Accessibility Statement
  • Budget & Performance
  • Contracting
  • EPA www Web Snapshot
  • Grants
  • No FEAR Act Data
  • Plain Writing
  • Privacy
  • Privacy and Security Notice

Connect.

  • Data
  • Inspector General
  • Jobs
  • Newsroom
  • Regulations.gov
  • Subscribe
  • USA.gov
  • White House

Ask.

  • Contact EPA
  • EPA Disclaimers
  • Hotlines
  • FOIA Requests
  • Frequent Questions
  • Site Feedback

Follow.