Looking at a map of annual temperatures across the U.S., it’s clear that the entire country is getting hotter. But when you zoom in on a new app that shows county-level heat data, disparities emerge. That app is based on research that looked at surface temperatures within more than 1,000 U.S. counties and found that for a majority, areas with higher rates of poverty can be nearly 7 degrees hotter in the summer than the richest communities nearby.
Income difference isn’t the only factor associated with higher temperatures; that research, from the University of California San Diego’s School of Global Policy and Strategy, found that even when controlling for income, non-white neighborhoods were hotter than the predominantly non-Hispanic white areas.
To get these findings, which were recently published in the journal Earth’s Future, researchers used satellite data that measured land surface temperatures for 1,056 U.S. counties that have 10 or more Census districts, and compared those measurements to Census-district demographic information. Temperature can vary so much across an area, says Susanne Benz, lead author of the paper who was a postdoctoral fellow at UCSD at the time of the study, that it wasn’t enough to look at temperature measurements from individual weather stations, which can be spread out over wide geographic areas. Satellite data allowed Benz and her postdoctoral supervisor Jennifer Burney to look at temperatures across all developed land in the continental U.S.