On June 22, 2019, the Smithsonian marks the first Saturday of summer—Solstice Saturday—by staying open late and hosting parties, programs, and performances. Many Smithsonian museums will be open until midnight welcoming visitors to the free festivities.

Solstice Saturday is held in association with By The People and Hofstra University’s Department of Physics and Astronomy. By The People is an international arts and dialogue festival taking place across Washington, D.C. The Smithsonian's Arts and Industries Building is the central hub for the festival, which runs June 15–23, 2019, with art installations, programs, and performances. Hofstra University’s Astronomy Festival on the National Mall takes place Saturday, June 22, 6–11 p.m. in front of the Smithsonian Castle. The Festival, now in its 10th year, features solar, optical, and radio telescope observations; hands-on activities, speakers from scientific and educational organization, and a chance to mingle with astronomers.