Hawaii, the last state with an indoor mask mandate for public schools, will make masks optional.

Hawaii has stuck with mask mandates longer than any other state. It waited until late March, when the first Omicron surge was receding, to drop its requirement for most indoor public settings — and even then, the requirement was retained for public schools.

But that rule, the last statewide school mask mandate in the United States, will be scrapped on Aug. 1, when most public school students in Hawaii will return to the classroom for the new school year, state officials announced on Tuesday. (The state lifted its outdoor mask mandate on school campuses in early March.)

“We really are looking at trying to move toward a more normal classroom experience this fall,” Dr. Sarah Kemble, the state epidemiologist at the Hawaii Department of Health, said at a virtual news conference. “This is the best opportunity we’ve had yet to move toward this new normal.”

To help achieve that goal, she said, masks will become optional inside Hawaii’s public schools, and quarantines stemming from classroom infections will no longer be required. Instead, mask use indoors will be recommended for specific classrooms if there is a cluster of infections in that class, Dr. Kemble said.

Face coverings in schools will only be “highly encouraged,” not required, Dr. Kemble said, when the Centers for Disease Control and Prevention determines community levels of Covid-19 to be “medium” or “high.”

The C.D.C. uses local hospitalization rates and measures of hospital capacity, in addition to case counts, to make its determinations, which are meant to help people decide for themselves whether to wear masks or take other precautions. Where levels are high, the C.D.C. recommends wearing a well-fitting mask indoors in public, including in schools, regardless of vaccination status.

Nearly 60 percent of counties in the United States currently have low community Covid-19 levels, according to this measure. But of Hawaii’s four counties, three are in the high-risk category and one is rated as medium-risk.

“The Covid landscape has changed — we’re at a different trajectory in the pandemic,” Dr. Kemble said in discussing the end of the school mask mandate. She cited several factors behind the decision, including the wide availability of vaccines for all age groups and ample supplies of testing kits.

Top federal health officials urged Americans this week to do more to protect themselves from Covid because of rising levels of a rapidly spreading Omicron subvariant known as BA.5. The officials pointed to a wide range of strategies, including the C.D.C.’s mask recommendation for high-risk counties.

“You can be previously infected — even as recent as the last couple of months — and have a very high rate of reinfection,” said Dr. Ashish K. Jha, President Biden’s coronavirus response coordinator. Experts say there is no evidence BA.5 causes more severe disease than earlier versions of the virus did.

Dr. Anthony S. Fauci, Mr. Biden’s chief medical adviser for the pandemic, said that “we should not let it disrupt our lives, but we cannot deny that it is a reality that we need to deal with.”

About 44 percent of Hawaiian children aged 5 to 11 are fully vaccinated, as are 85 percent of 12- to 17-year-olds, according to the C.D.C. But only 26 percent of adolescents 12 to 17 have received boosters, Dr. Kemble said.

“You don’t know if the student in class sitting next to your child is going to be masking or not, so now is a really good time to boost,” she said, urging parents to get their children vaccinated before the new school year begins.

Heidi Armstrong, the interim deputy superintendent of the state’s education department, noted that the state’s indoor mask mandate was unpopular with some families. But she emphasized on Tuesday that it succeeded in keeping many more students in the classroom after the disruptions of the pandemic’s early months.

Ms. Armstrong said that even though the mandate is ending, any student, teacher or employee who wants to wear a mask indoors “will have that choice absolutely respected.”

The Hawaii State Teachers Association has expressed concern about the quality of ventilation in many schools, and is recommending that its members continue to wear masks indoors to maximize the chances of staying healthy, because of a shortage of substitute teachers.

“In order for the mask mandates to be lifted successfully, we need to have clear mitigation strategies in place,” Logan Okita, the group’s vice president, said in a statement on Tuesday.

Ms. Okita, an elementary schoolteacher in Oahu, said that Tuesday’s announcement allowed teachers, students and families “to have time to process that information and make decisions and have those conversations at home.”