Schools will open this fall in much of the Washington region a little less normal than expected — with mask requirements now planned for Fairfax and Arlington counties, along with D.C. and Montgomery and Prince George’s counties.

School systems are issuing the mandates regardless of vaccination status — to the relief of some families and teachers, and to the dismay of others.

The recent decision in Fairfax County, the largest system in Virginia, follows a shift in school guidance from the Centers for Disease Control and Prevention. On Tuesday the federal agency updated its guidelines to include a recommendation that face coverings be required inside of schools as students begin the coming academic year.

The mandates come as the highly contagious delta variant of the coronavirus continues to drive up infection rates in communities across the country and safety considerations are on the rise once again.

Fairfax County school officials announced Wednesday that masks are a must for the fall — to be worn indoors by students and employees, as well as on school buses. Face coverings are not required while eating or outdoors for recess or other activities, Fairfax officials said.

“Universal masking is a critical factor in ensuring all students can return to our buildings, especially when social distancing is not possible and not all our students are eligible yet for vaccinations,” an email to the Fairfax County community said.

The school system assured parents it would regularly review masking practices and pay close attention to national, state and local recommendations.

At the Arlington School Board meeting Thursday evening, the superintendent made an announcement similar to that made by Fairfax: Masks would be required for everyone — vaccinated and unvaccinated — in school buildings and on school buses this fall.

School systems across the region have been planning for a return to full-day in-person learning when schools open for the fall — five days a week, as close to normal as possible as the pandemic continues.

State officials in Virginia had previously urged school systems to require masks when schools open again but left it up to local officials to make the call.

Alexandria said the issue will be up for discussion at a School Board meeting in early August. Loudoun County has not announced its masking policy for fall, a spokesman said.

The decisions in suburban Virginia school systems follow similar actions in Maryland and in D.C.

School board members in Montgomery County, home to Maryland’s largest school system, voted on Tuesday to support a recommendation to require masks for the fall. School leaders pointed to an increase in coronavirus cases and advice from the American Academy of Pediatrics, which has recommended universal masking in schools for everyone over the age of 2.

Montgomery County officials pointed to uncertainties related to variants and noted that not everyone is vaccinated. Children under the age of 12 are not yet eligible for coronavirus vaccines.

A day earlier, Monica Goldson, chief executive of Prince George’s County Public Schools, announced a mask mandate, citing vaccination trends among county teenagers and the goal of reaching a rate of at least 70 percent before considering lifting the masking requirement.

Other school systems are part of the same wave.

In Maryland’s Frederick County, Superintendent Theresa Alban announced Wednesday that masks will be required when students return to school Aug. 18 — a move to help stem the spread of the virus and keep schools open.

And in D.C., Public Schools Chancellor Lewis D. Ferebee said last week that everyone — vaccinated or not — would be required to wear masks in school buildings in the fall.

The same goes for the city’s large charter school sector, said Michelle Walker-Davis, head of the D.C. Public Charter School Board.

For Lawrence Wade, the requirement is reassuring.

Wade, who has a 4-year-old daughter in prekindergarten at a KIPP DC campus along Benning Road SE, considers the mask mandate a “great thing” that makes the school safer for all. Wade is involved in the school and expects to visit often.

He said his daughter has been wearing a mask for nearly half her life and, even though she is just 4, she can keep it on all day.

“I feel 100 percent safer with the mask requirement,” said Wade, a small-business owner and government contractor.

Elsewhere, Brigid Meyer, a physical therapist for the Montgomery County school system, welcomed the change.

“I am so thrilled,” she said. “I feel like it protects the unvaccinated and is for the good of everyone.” She said she only wished that the masking requirements would extend to the home visits she makes to work with young children.

Erika Norman, a parent in Kensington, Md., was not surprised by the masking decision and hopes that one day, when case numbers improve, masks will be optional. For now, she said, she mainly hopes there remains a “true commitment” to five-day-a-week full-day learning inside school buildings.

“Certainly school with masks is way better than no [in-person] school for me,” she said.