Students in Seattle are likely to go to school in person only once or twice a week, officials said. Half of Omaha’s students will attend Monday and Tuesday, and the other half Thursday and Friday, rotating Wednesdays. And Fairfax County, Va., outside Washington, said students would spend at least two days a week in class, with the rest online.

The governors of Connecticut and New Jersey announced guidance that they said would allow students to return to school, but left the details up to districts, with Gov. Phil Murphy of New Jersey acknowledging on Friday that some schools would likely need to adopt a hybrid model and restrict daily attendance…

Reopening decisions are likely to vary greatly based on the size and density of districts, as well as region. In the South and West, where political leaders have been more eager to reopen their economies despite a recent upswing in coronavirus cases, school systems may be more likely to return to a full-time schedule, albeit with distance restrictions, new sanitation procedures and mask recommendations.