Science  /  Study

Racist Housing Practices From The 1930s Linked To Hotter Neighborhoods Today

A study of more than 100 cities shows neighborhoods subjected to discriminatory housing policies nearly a century ago are hotter today than other areas.

In cities around the country, if you want to understand the history of a neighborhood, you might want to do the same thing you'd do to measure human health: Check its temperature.

That's what a group of researchers did, and they found that neighborhoods with higher temperatures were often the same ones subjected to discriminatory, race-based housing practices nearly a century ago.

In a study of 108 urban areas nationwide, the formerly redlined neighborhoods of nearly every city studied were hotter than the non-redlined neighborhoods, some by nearly 13 degrees.

Redlining refers to the federal government's practice in the 1930s of rating neighborhoods to help mortgage lenders determine which areas of a city were considered risky. The federal Home Owners' Loan Corporation made maps and shaded neighborhoods red that it deemed "hazardous." That risk level was largely based on the number of African Americans and immigrants living there. The practice, along with the other segregationist housing policies of the time, had lasting effects — from concentrating poverty to stifling home ownership rates.

You can still feel those effects — literally. Nearly 90 years after those maps were created, redlined neighborhoods are hotter than the highest-rated neighborhoods by an average of almost 5 degrees, according to the research from Portland State University, the Science Museum of Virginia and Virginia Commonwealth University.

"It's like stepping into a parking lot from a park. You would feel that relatively quickly," says Vivek Shandas, a professor of urban studies and planning at Portland State University, who co-authored the study. "It was very surprising when we saw that it was a pattern that we were seeing consistently across the country."

The link between higher heat and redlined neighborhoods, many of which are still struggling economically from decades of disinvestment, echoes the findings of a joint investigation last September by NPR and the University of Maryland's Howard Center for Investigative Journalism. In an analysis of heat and income in 97 of the most populous U.S. cities, we found low-income areas in the vast majority of those cities were more likely to be hotter than their wealthier counterparts. Those poorer areas were also disproportionately communities of color.