WASHINGTON -- In August, a team of citizen scientists mapped-out which DC neighborhoods are most dangerously hot when temperatures rise, and after examining the results, they're concerned for DC's poorest residents.

After hours of mapping-out more than 75,000 temperature data points, the result is a district heat map showing Washington, D.C.’s Urban Heat Island Effect. The date surveyed was August 28, 2018.

The citizen scientists drove the same route (aka traverse) three different times the day they measured.

They found a striking temperature difference between certain parts of town.

Most of Northwest D.C. stayed in the 84-94 degree zone.

On the other side, a large swath of Northeast, the National Mall area and parts of Southeast, like Anacostia, hit 94–102-degrees.

David Herring says one of the most surprising and significant finding was the potential 17-degree temperature difference.

“It might be 86 degrees in one part of the city, it could be as hot as 103 degrees in other parts of the city during exactly the same time,” said Herring.

DC Heat maps cropped
DC temperature difference maps

David Herring is the Climate Program Officer of Communications Manager with NOAA, the National Oceanic and Atmospheric Administration.

Herring sponsored the joint study that looked at both Baltimore and DC’s hottest neighborhoods. In DC, the hottest includes: Queens Chapel, Michigan Park and Bloomingdale. Parts of Anacostia also show up in rich Orange.

In blue, “The cooler temperatures are areas that were much more vegetated – had much more tree canopy,” said Herring.

The blue areas, like Rock Creek Park and its surrounding neighborhoods, do not have as much blacktop and large buildings.

Here’s where Herring is concerned.

If you compare the DC Urban Heat Island Effect map to a DC Median Household Income map created by the DC Policy Center, you see many of the areas marked orange for sweltering heat, are also some of the city's more impoverished neighborhoods.

The darker the shade on the map, the higher the average median income.

Washington DC Median household income
Washington, DC Median household income (Source: City-data.com)
O'Keefe, PJ

Herring made a point to say, those stuck in the dangerous heat include a lot of the elderly and people who maybe can’t afford air conditioning.

“They may not be able to get out of harm's way and as this problem gets progressively worsens with each decade, it starts to become an equity issue and social justice issue where there’s a disproportionate exposure to this hazard,” said Herring, “Yeah, my concern continues to grow.”

Some newer and more expensive communities such as NoMa are also in that orange area.

"What we're hoping is that the cities (DC and Baltimore), will begin to factor these data and these maps into their long-range planning. What climate change models project over the course of this century is that on days like we experienced, on the days that we made those measurements - temperatures reached about 95 degrees -- and over the course of this century, the number of days in both Washington, D.C. and Baltimore where temperatures are projected to reach that high could go up to as-many-as 80 days out of the year or more," said Herring.

Heat map income map comparison

To view Baltimore & DC’s interactive heat maps, click here.