Ms. Reynolds has said she is prioritizing the needs of the most vulnerable students, and the state’s Education Department has threatened to require Des Moines to extend its school year — at a cost of about $1.5 million a day — if it does not comply with state regulations.
But the local school board has argued that the high caseload in Polk County, which includes Des Moines, makes it unsafe to hold in-person classes.
Of the more than 80,000 coronavirus cases in Iowa, Polk has more than 15,000, the most of any county in the state by far, according to a New York Times database.
The Des Moines school board on Monday voted 6 to 1 to start phasing in a “hybrid return to learn” plan. Preschool students will begin returning on Oct. 12, followed by elementary, middle and then high school students by Nov. 10, the Des Moines Register reported.
However, the board delayed setting an infection rate that would force the district to revert to remote learning, deciding instead to invite public health issues to provide guidance on the subject at a subsequent meeting. That means the planned return to class could still be delayed.
Iowa officials have said that 15 percent of a county’s coronavirus tests must be positive over a two-week period before its schools can close their doors — a threshold that is at least triple what many public health experts have recommended. The rules also say that districts in counties that remain below 15 percent must offer at least 50 percent of their classes in person.
In two weeks across late August and early September, Polk County had an average positivity rate of about 8 percent.
Reporting was contributed by Livia Albeck-Ripka, Stephen Castle, Troy Closson, Ben Dooley, Marie Fazio, Rick Gladstone, Abby Goodnough, Andrew Higgins, Jan Hoffman, Mike Ives, Anatoly Kurmanaev, Sharon LaFraniere, Apoorva Mandavilli, Victor Mather, Patricia Mazzei, Patrick McGeehan, Raphael Minder, Claire Moses, Aimee Ortiz, Campbell Robertson, Simon Romero, Dagny Salas, Anna Schaverien, Christopher F. Schuetze, Megan Specia, Sheryl Gay Stolberg, Eileen Sullivan, Noah Weiland, Katherine J. Wu, Elaine Yu, Carl Zimmer and Karen Zraick.