The National Gallery of Art (NGA) in Washington, DC, will close on November 21 owing to a recent local and nationwide spike in Covid-19 cases, the institution announced yesterday. All seven of the city’s Smithsonian’s museums and the National Zoo will close on November 23. Neither the NGA nor the Smithsonian has offered a reopening date, but the closures are expected to last through the winter holidays, typically one of the busiest times of year for the museums.The news comes just days after the announced November 20 closures of Philadelphia institutions the Philadelphia Museum of Art, the Academy of Natural Sciences of Drexel University, the Barnes Foundation, the Eastern State Penitentiary Historic Site, and the Pennsylvania Academy of the Fine Arts. In accordance with a gubernatorial order mandating statewide closure of institutions, The Art Institute of Chicago closed earlier this week, with the rest of the city’s major institutions including the Field Museum and Shedd Aquarium expected to close today. Responding to a similar governmental order, all Twin Cities museums are closing as well, among them Minneapolis’s Walker Art Center and Minneapolis Institute of Art, both of which go dark on November 21, with the former remaining shuttered until at least January 2, and the latter likely to remain closed for at least a month. Nearly all Denver museums, including the Clyfford Still Museum and the Museum of Contemporary Art Denver, are performing mandated closures today, though the Denver Museum of Art will remain open, having received a variance from the state. In California, most Los Angeles indoor institutions remain closed, with closure extended this week; Bay Area institutions continue to operate at 25 percent capacity.Second-wave Covid-19 closures further imperil the nation’s museums, many of which are operating on wafer-thin margins, and some of which may not reopen in the wake of the crisis unless measures are taken by state and federal governments.