Capitol Hill Restoration Society

Lights-Out Hour DC

Posted on March 18th, 2023

Lights-Out Hour DC, which coincides with international Earth Hour, is a voluntary event coordinated by the DC chapter of the International Dark-Sky Association. To participate, dim or extinguish non-essential lights for one hour beginning at 8:30 pm on Saturday, March 25.Dozens of cities across the globe have observed Earth Hour since 2007, to help draw public attention to climate change and the impact of light pollution on public health and the environment. Iconic structures such as the Golden Gate Bridge, the Empire State Building, and the Eiffel Tower have gone dark. Join with cities around the world in a gesture of solidarity by “switching off” for one hour. Please spread the word about Lights-Out Hour DC.

Why Go Dark?
Building energy use accounts for nearly 75% of the District’s greenhouse gas emissions. Reducing unnecessary lighting helps the District address climate change.
Pervasive nighttime lighting disrupts our circadian sleep-wake cycle. Exposure to high levels of outdoor light at night is associated with multiple health disorders. 
Artificial light at night disrupts wildlife. In dense urban areas, it disorients migratory birds, leading to exhaustion, predation, or lethal collisions with buildings.
Stars have been part of human culture for millennia. Because of outdoor lights, DC residents are among the 80% of North Americans who can’t see the Milky Way, our home galaxy.

To find out more, visit
For further information or to volunteer, please contact the D.C. Chapter of the International Dark-Sky Association at
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