Yo Philadelphia public school parents and guardians -- be sure to send your child masked up to class Monday.

The School District of Philadelphia said that starting Monday, May 23, 2022, students and staff once again must wear face masks in classrooms, citing an increase in COVID-19 infections.

Families had a weekend to prepare. The district made the announcement in a news release Friday afternoon, saying that the Philadelphia Department of Public Health made the recommendation for universal mask-wearing. Masking will be mandatory “until further notice,” the district said.

Mask wearing will be required at all times on campus and while riding on school buses and vans in schools in Pennsylvania's largest school district.

“As we’ve learned since the pandemic began, the coronavirus continues to evolve and so too will our response to it. As we work together to minimize the spread, please remember that our Health and Safety Protocols are still in effect, including the importance of notifying the District if you test positive for COVID-19,” Superintendent William Hite said in the district statement.

The mask requirement for Philadelphia public schools followed the announcement last week that the Cheltenham and Lower Merion school districts in neighboring Montgomery County would also require masks again. Lower Merion, however walked back its requirement to a strong recommendation instead.

In Montgomery County, the Norristown Area School District also started requiring masks in schools starting Monday.

Also over the weekend in Montgomery County, the Abington and Upper Dublin school districts announced they would be strongly recommending masks, but not require them. The Wissahickon School District also started “strongly recommending” masks in all buildings.