California’s governor has announced strict rules for school reopening that would prevent the vast majority of students from returning to classrooms in the fall as coronavirus cases hit their highest levels yet in the state.

Governor Gavin Newsom announced the new guidance on Friday, which mandates that public schools in California counties that are on a monitoring list for rising coronavirus infections cannot hold in-person classes, and will have to meet rigorous criteria for reopening.

With 31 of California’s 58 counties now on that monitoring list, including the state’s most populous areas, that would mean most of the state’s 10,000 schools are unlikely to start the school year with in-person instruction.

Schools will be allowed to reopen for in-person instruction only when the counties they are located in have been off a statewide monitoring list for 14 days, based on stable case rates.

The guidelines also includes requirements for PPE, physical distancing, distance learning and guidance for what should happen if students get sick.

Masks, for instance, will be required for students in third grade and older – for students in second grade and younger, masks or face shields (which can be less intimidating to youngsters) will be strongly recommended. Staff must maintain 6ft between each other and students, where possible, and each day would begin with checks for symptoms.

If 5% of students at a school are sick, it would mandate school closure. If a quarter of a district’s schools are closed within a two-week period, all district schools will close.

Distance learning, which saw a disastrous rollout in spring, will also have new requirements: connectivity and devices for all kids; a requirement of daily live interaction with teachers and others students, assignments that are comparable to in-person classwork and lessons adapted for English learners and special education students.

The announcement comes just weeks before many of the state’s 1,000 school districts return to classes in mid-August, with many still finalizing their reopening plans.

The governor’s strict new regulations marked a dramatic shift from his earlier position that it was up to local school districts and boards to decide when and how to reopen, and creates the first statewide approach to the issue. Until now, counties have been allowed a wider degree of discretion in how to move forward, creating an uneven patchwork of plans.

That was seen this week when the state’s two largest school districts in Los Angeles and San Diego, announced they would open the school year with online classes only. Meanwhile, education officials in Orange county, located between the two, recommended that students return to school with in-person instruction, without the use of masks.

The recommendations endorsed by the Orange county officials made the case that masks can lead to anxiety, depression and even learning disabilities – a claim, one doctor told the Guardian, that was not backed by any evidence that he was aware.

An educational consultant told EdSource that Newsom made the decision to support school staff and insulate district officials from angry parents who want schools to reopen for in-person classes. Newsom’s move effectively takes that decision out of the hands of county school officials.

Agencies contributed reporting