Seattle’s Hidden Urban Heat Crisis: How We Can Fix It

Seattle’s summers are getting hotter, and not everyone is feeling the heat equally. Historically redlined communities are among the most vulnerable to the impacts of rising temperatures. Redlining was a discriminatory practice where financial services, such as mortgages and insurance, were intentionally denied to residents of certain neighborhoods based on their race or ethnicity. Although redlining is now illegal, the legacy of this practice persists in urban environments, and these neighborhoods often have less tree cover and fewer green spaces, leaving them disproportionately exposed to urban heat.

This inequity in urban design has real consequences. According to Science Friday, “heat is America’s deadliest weather hazard, killing an estimated 12,000 people every year.” Seniors and those who cannot afford air conditioning are among the most at risk. Research by the NIH, University of Washington, and the U.S. Department of the Interior confirms that tree cover can significantly mitigate urban heat, cooling neighborhoods and reducing health risks during heatwaves. Similarly, the EPA notes that green infrastructure, such as urban forestry, can lower temperatures by up to 10°F, making it an essential tool for combating urban heat.

This issue is particularly relevant for Seattle, where previously redlined districts may still experience disparities in tree coverage, putting residents at a higher risk of heat-related health issues. An urban heat island analysis by Earth Economics reveals that maximum temperatures in some parts of Seattle have risen by as much as 6°F above the local baseline. Regional climatic effects further compound this issue, with neighborhoods in Central and South Seattle being as much as 14°F hotter than those in North Seattle. These hotter areas tend to have fewer green spaces, more paved surfaces, and a higher prevalence of low-income households. The analysis notes that there is a “strong correlation between household income and urban heat islands [in Seattle].” The public health burden of urban heat islands is disproportionately levied on the lowest-income households. These disparities echo the findings from The New York Times, which reported similar patterns in more than 100 cities nationwide. Creating green spaces helps reduce heat retention in dense urban areas, making them a key solution for addressing urban heat, especially in lower-income neighborhoods. 

Students from the Community Engagement Center started regular volunteer sessions at the Harrison Ridge Greenbelt near Bush at the end of last year. The greenbelt sits on 6 acres of protected woodland in the Madison Valley neighborhood of Seattle's Central Area. Since 1995 community members have been restoring this urban forest to its natural state, clearing away invasive species like blackberry and ivy and replacing them with native plants that thrive here. In the last 5 years, over 1900 plants have been planted, including 175 conifers, that provide habitat for small mammals and bird species that forage and build their nests in the greenbelt. Urban green spaces, like the Harrison Ridge Greenbelt, are vital in allowing heat to escape from urban areas. 

We have a chance to cool down our city and make it greener for everyone—especially those most affected by rising temperatures. The time to act is now. Investing in urban forestry not only promotes a healthier environment but also fosters a more equitable and resilient city. Students love volunteering at the greenbelt and playing with the resident dog, Cherry. It is a great space to escape with your friends to leave the troubles of school behind. Want to be part of the solution? Join your classmates in volunteering at the Harrison Ridge Greenbelt to make Seattle a cooler, greener place for all. Please reach out to Samuel Checkal ’27 to get involved today!