Hot Summer Days

Many people think Washington, D.C. was built on a swamp. Is this fact or fiction?

Historians confirm that this is fiction and that Washington D.C. is not built on swampland. This rumor is rampant during the hot and muggy summers in the city. Rather, our nation’s capital has one of the worst urban heat island effects in the country. Summers in Washington D.C. can be very hot! The city can be up to 11.5°C (21°F) hotter than rural areas and averages 17 more days above 32.2°C (90°F) per year than the surrounding regions.

A runner jogs by the memorials on a hot summer day. (© Anton Ivanov/Shutterstock)
One of the many tree lined streets in Washington, D.C.
(© Anton Ivanov/Shutterstock)

The Department of Energy and the local electric company work together to plant trees in areas that will increase its cooling effects. They plan to plant 8,600 new trees in the city by the year 2032, with a large number of those trees lining the streets of the city.

A NASA satellite image of Washington, D.C. showing the greenery around the city. (Greenery/plants shown in red).
(NASA)
This graph shows the percentage of Washington, D.C that is covered by plants and the goal for the year 2032.
(Dept. of Energy & Environment)

Apart from reducing UHI effects, planting trees has other economic and social benefits. Trees can lower energy costs, reduce air pollution and greenhouse gases, protect from ultraviolet radiation, decrease stormwater runoff, increase property value, and improve quality of life.

Th Lincoln Memorial sits at one end of the National Mall.
(© Martin Falbisoner/Wikipedia)

Portland, OR

Population: 609,456

Urban Forests

Explore

Las Vegas, NV

Population: 603,488

Urban Sprawl

Explore

Chicago, IL

Population: 2,719,000

Green Roofs

Explore

Washington, DC

Population: 658,893

Tree Lined Streets

Explore

Cairo, Egypt

Population: 7,772,000

Old Meets New

Explore

Stuttgart, Germany

Population: 597,939

Designing from the Ground Up

Explore
  • absorption

    noun

    A type of transfer where a substance takes in another substance or energy.

  • conservation

    noun

    The protection of something in the natural world.

  • evapotranspiration

    noun

    The transfer of water from plants into water vapor in the atmosphere.

  • mitigation

    noun

    The process of limiting the impact of something.

  • preservation

    noun

    The action of taking care of or protecting something.

  • sequester

    verb

    To take in or isolate something.

  • atmosphere

    noun

    A layer of gas that surrounds the surface of a planet.

  • erosion

    noun

    The movement of broken down, or weathered, material.

  • greenery

    noun

    Plants or vegetation

  • photosynthesis

    noun

    The process plants use to make food from sunlight, carbon dioxide, and water.

  • radiate

    verb

    To give off energy, such as heat, in the form of waves.

  • storm water

    noun

    Excess water from a storm the ground cannot absorb quick enough.

  • concentration

    noun

    A relatively close cluster of objects.

  • evaporation

    verb

    The process a liquid goes through to change into a gas.

  • habitat

    noun

    The natural environment of an organism.

  • pollutant

    noun

    A substance that is considered to be unnatural or undesired in the environment and can cause harm to plants or animals.

  • runoff

    noun

    Water from rain or snow that flows over the surface of the land.

  • vegetation

    noun

    Any and all plant life found in a particular area.