The Poor & Urban Heat Islands

In August 2018 NOAA ran a citizen science project in Washington D.C. and in Baltimore to discover which part of those cities were effected by urban heat islands. You can see the results of this study on NOAA's Detailed maps of urban heat island effects in Washington, DC, and Baltimore.

The detailed maps produced by NOAA show that the hottest areas in both cities are the areas with the densest built environment and the most roads. This is a result of un-shaded roads and buildings absorbing heat and then radiating it out to their surroundings. The coolest places in both cities are in parks or in other areas with lots of tree cover. The dark surfaces of roads and built materials, such as bricks and concrete, absorb more heat than grass and vegetation. Which is why the densest built areas tend to be significantly warmer than areas with tree cover or parks.

Guess who lives in areas with parks and trees and guess who lives in densely built areas with lots of bricks and concrete. That's right the hottest areas in cities tend to be the areas where the poorest residents live, while the richest residents can afford to live in the coolest areas with lots of parks and trees. You can observe this pattern in cities across the USA using NPR's interactive heat island maps.

In As Rising Heat Bakes U.S. Cities, The Poor Often Feel It Most NPR has published an interactive tool which allows you to view heat island maps of US cities side-by-side with a map of income levels. Using this comparative tool you can directly see if there is any correlation between high surface temperatures in a city and the level of income. When you select a city the tool even tells you directly if there is a strong, moderate or weak link between surface temperatures in the city and where different income groups live.