Heat Islands - What They Are and How To Protect Yourself

Many places, including Fairfax County, are seeing hotter weather and more extreme heat than in previous years. 

When heat strikes, neighborhoods with less greenery and more buildings and pavement can get much hotter than surrounding areas. These hot spots, known as Urban Heat Islands, can have warmer temperatures during the day and at night, making it difficult for people to keep cool in these areas.

Heat Islands in Fairfax County

Annandale, Bailey’s Crossroads, Centreville, Hybla Valley, Merrifield, Seven Corners, Springfield and Tysons are some of the hottest areas in Fairfax County. 

View our Resilient Fairfax interactive map to see average temperatures in your neighborhood and across our communities. Explore different features showing population data, transportation options and natural resources like tree canopy, parks and bodies of water.

Who is at Risk?

Everyone can be affected by heat, but some people are more at risk than others, especially if they work, live or exercise in heat islands:

• People who work outside, such as construction workers, landscapers, emergency responders, arborists, trash/recycling crews, delivery drivers and park employees, because they spend a lot of time outdoors and often perform strenuous activity while outside.
• People who live in urban heat islands, particularly if they don’t have reliable access to air conditioning or transportation.
• People who exercise outside, including children, students and adults, are more likely to become dehydrated and get heat-related illness.
• Economically disadvantaged communities, because they are more likely to lack access to air conditioning.
• Older adults, children and people who are pregnant, because they are more sensitive to heat and their bodies have a harder time cooling down.
• People with chronic medical conditions, disabilities or access and functional needs, because heat can worsen existing symptoms, increase strain on the body and interfere with certain medications.
• People experiencing homelessness, who typically have less access to cooling and transportation. 

Learn more about how heat can affect your health and how to protect yourself and your loved ones. 

What We're Doing to Help

We are working to reduce urban heat islands and help keep you safe in the heat in several ways:

Resilient Fairfax – Resilient Fairfax is the plan to adapt and become more resilient to changing climate-related conditions such as extreme heat, severe storms and flooding. Since it was adopted by the Board of Supervisors in 2022, the plan is being implemented by an interagency team of over 25 county agencies. Resilient Fairfax includes 48 strategies to create climate-ready communities, adaptive environments, resilient infrastructure and buildings, and integrated action planning. These strategies include enhancements to many of the programs and policies listed below.

Heat-related outreach and education – County agencies collaborate to provide heat-related outreach and education to residents through in-person events, webinars, informational materials and more. 

Heat protocols for athletes and recreation – Fairfax County Public Schools has heat-related protocols in place for outdoor sports and recreation to ensure that students are safe during high temperatures. These include protocols for hydration, practice length, breaks, uniforms and equipment, and types of physical activity permitted for specific temperatures.

Homeless Healthcare Program – The Homeless Healthcare Program ensures that unhoused Fairfax residents receive care for chronic and acute health conditions, have their prescriptions refilled, and are connected to dental and eye care services. During hot months, the program ramps up its street outreach to provide healthcare services and heat-related illness prevention education to unhoused populations.

Health in All Policies – Health in All Policies is a strategy to integrate health considerations into policy decisions across other sectors, like transportation or stormwater planning, to improve public health. As part of this approach, proposed revisions to the county’s Comprehensive Policy Plan include new policy guidance promoting climate health, with a significant focus on reducing heat islands by utilizing green infrastructure solutions, particularly in areas of the county more vulnerable to the effects of high heat.

Cooling Centers – When Fairfax County’s heat plan is activated, cooling centers around the county will be available during normal operating hours for individuals needing relief from the heat. Fairfax County will activate its heat plan when the National Weather Service issues an advisory, watch or warning (usually 24 hours in advance).

Senior Cool Care Program – The Senior Cool Care Program is a program that helps low-income older citizens in our jurisdiction keep cool during summer months. This program does not provide financial assistance, but it provides additional cooling at home by providing air conditioning units, window air conditioning units or fans for eligible older adults, age 60 and older. The program runs May 1 through Oct. 31.

Cooling Assistance Program – The Cooling Assistance Program helps households manage cooling costs during the hottest months of the year. Assistance includes payment of electric utility bill, cooling equipment repair, purchase of a window or portable A/C unit and/or a one-time payment of an electric security deposit. Program eligibility requires households include individuals who are age 60 or older, 5 or younger, or someone with a disability. Applications for cooling assistance are being accepted until Aug. 15.

AC Rescue – This new program provides small air conditioning (AC) equipment for county residents who are unable to receive help from other cooling programs. There are no age or disability requirements, and the program is open year-round to residents who make up to 80% area median income. The program is administered by the Office of Environmental and Energy Coordination in partnership with Rebuilding Together. For more information, visit AC Rescue or call 703-324-7262.

Tree Canopy – Tree canopy is one of Fairfax County’s most effective defenses against urban heat islands. Trees provide shade, reduce pavement and building surface temperatures and cool the air through evapotranspiration. Land Development Services (LDS) plays a key role in preserving and expanding this critical green infrastructure. Through the site development review process, LDS enforces requirements for tree preservation and replanting, particularly in areas vulnerable to high heat. LDS also guides updates to technical standards and policies that promote the use of native and climate-resilient tree species, helping ensure long-term canopy health and function. By integrating tree canopy goals into land development, LDS supports countywide efforts to reduce localized heat impacts and advance climate adaptation.

Heat Resilient Design – As part of the Resilient Fairfax plan, the county is implementing heat-resilient design guidelines in various county policies and design guidelines. Heat-resilient design concepts include cool roofs, cool pavements, passive cooling, green infrastructure, building orientation to reduce sun exposure during the hottest months, ventilation options, sufficient natural and architectural shade, and more.