WASHINGTON—As the U.S. housing crisis and climate change worsen, people living in affordable housing are among those at high risk of unhealthy, dangerous or even deadly conditions due to extreme heat, according to a Union of Concerned Scientists (UCS) analysis released today.
“Extreme heat is the deadliest climate impact and is colliding with the nation’s long-standing shortage in safe, affordable housing for people with the lowest incomes,” said Zoe Middleton, a co-author of the analysis and associate director for just climate resilience at UCS. “As policymakers grapple with how to address the worsening climate and housing crises, they must take the health threat of extreme heat seriously by boosting investments in home weatherization, energy bill assistance, and climate-resilient affordable housing.”
For the report, “Colliding Crises,” UCS researchers analyzed the impact of extreme heat on nearly 8 million homes in key portions of the affordable housing market, including subsidized public housing, project-based subsidized housing, manufactured housing, and homes supported by the Low-Income Housing Tax Credit program. They looked at the exposure of these homes to county-level National Weather Service (NWS) heat alerts between May and October in 2024, the hottest year on record. UCS calls that period of the year “Danger Season” because it is when climate-fueled extreme weather is most active and dangerous in the United States.
The analysis found that most residents of the country’s affordable housing experienced at least seven days of National Weather Service (NWS) alerts for extreme heat, with nearly half enduring 21 or more days of those warnings. The largest shares of the nation’s affordable housing units that faced heat alerts among all regions were in the Northeast and Southeast, while Texas, California and New York led in numbers of exposed homes.
State and territory-specific findings in the analysis:
- Texas, New York, California, Florida and Ohio had the largest numbers of affordable homes exposed to one or more weeks’ worth of heat alerts in 2024.
- Texas, California, New York, New Jersey and Louisiana had the largest numbers of affordable homes exposed to three or more weeks’ worth of heat alerts in 2024.
- Puerto Rico, the District of Columbia, the U.S. Virgin Islands, Florida and New York had the largest percentage of households headed by a person of color that experienced heat alerts.
Affordable housing units are often old, built to outdated standards without access to cooling, and located where there is little shade. To reduce the risk to residents of heat-related illnesses, the analysis recommends federal, state and local governments take urgent actions to make new and existing affordable housing more heat-resilient and energy efficient.
The analysis found that people of color face disproportionate risks of exposure to dangerous heat, even accounting for their overrepresentation in housing considered affordable for those with low incomes. It found that a person of color headed the households of about half of all public and project-based housing exposed to one or more weeks’ worth of heat alerts and two-thirds of those units that endured three or more weeks’ worth of heat warnings.
“The health impacts of extreme heat are not equal,” said Dr. Juan Declet-Barreto, a co-author and senior social scientist for climate vulnerability at UCS. “People of color are already among those who live with the lowest incomes in the country, in substandard housing, and without access to cooling resources or the ability to afford the costs of running air conditioners. These conditions could make them more vulnerable to heat-related illness or even death as climate-driven extremes become more frequent and intense.”
Protecting the health and safety of people residing in affordable housing will require policy changes recommended in this analysis. They include making affordable housing more heat-resilient and safe; increasing access to cooling, home weatherization, efficiency, and energy affordability programs; providing robust recovery funding for people following climate or extreme weather disasters; safeguarding federal scientific expertise and climate and weather data; and ensuring decisionmakers heed the best available science.
Also, to reduce future harm and protect the most vulnerable, immediate actions must be taken to reduce heat-trapping emissions—an imperative for limiting future extreme heat. Many of the nation’s efforts to build resilience and cut emissions by transitioning to clean energy are now under relentless attack by the Trump administration.
“If we continue to burn fossil fuels, dangerous heat will worsen and the lives and health of people living in affordable housing will be at particular risk,” said co-author and UCS Director of Climate Science Dr. Amanda Fencl. “Policymakers at all levels must act now to sharply curtail heat-trapping emissions while also making investments in climate-resilient affordable housing.”
Related Resources:
- A UCS blogpost, “How to Protect Residents of Affordable Housing from Climate-Driven Extreme Heat.”
- A UCS blogpost, “Crisis Chocantes: El calor extremo y la crisis de vivienda asequible en Puerto Rico y las Islas Vírgenes.”
- The Danger Season 2025 map and the corresponding blog series.