In the absence of any state or federal order, mayors and city councils around Minnesota are passing local requirements to wear masks while indoors to limit the spread of the virus that causes COVID-19.

Already this week, the cities of Winona, Rochester, Mankato and Edina have enacted mask requirements, and similar mandates will be debated this month in Duluth and St. Cloud.

Minneapolis, St. Paul and the 63,000-student University of Minnesota require mask-wearing indoors, and the state Supreme Court mandated masks in all court facilities starting July 13.

In Rochester, home of Mayo Clinic, Mayor Kim Norton said Tuesday that she decided to support the city’s requirement to wear masks in public in part because so few people seemed to be wearing them. Olmsted County’s two-week average of new lab-confirmed cases of COVID-19 is higher than a month ago, putting the county at an elevated “orange” level of alert.

“I didn’t want to move into the red, and then have this huge issue like we’re seeing in Florida, Texas, Alabama and everywhere else,” Norton said. “I know it’s not 100 percent [effective at preventing the spread of the virus]. I’m the first one to admit that. But a solution to slow the spread that is so easy, so inexpensive — why wouldn’t we do it?”

In Edina, Mayor Jim Hovland signed an order that went into effect Monday requiring masks covering the mouth and nose while inside most public places in the city. The City Council will hold a special meeting Wednesday to decide whether to extend the policy.

“If we want our kids to go back to school in the fall, we’ve got to keep them practicing these important habits,” Hovland said in a Facebook post, advocating cloth masks in public, frequent hand-washing and social distancing.

Gov. Tim Walz has acknowledged that he’s considering whether to impose a statewide order. The Minnesota Medical Association, the state Department of Health and the Minnesota Nurses Association are each urging a statewide order.

On the other hand, the Minnesota Chamber of Commerce has said a flexible policy around masking could help reopen the state economy.

Non-medical-grade fabric masks that can be bought in stores or made at home are widely thought to trap the microscopic droplets in a person’s breath that can spread the virus to the people around them.

Similar to a surgical mask worn by a doctor in an operation, a fabric mask worn during a coronavirus pandemic does not protect the wearer, but rather, the people nearby. The tight-fitting N95 respirators worn by doctors and nurses do protect the wearers, but they’re in such short supply that they’re generally reserved for on-the-job health care workers.

Supporters of wearing cloth masks in public say there’s widespread scientific support.

The Minnesota Medical Association noted that a recent non-peer-reviewed paper in the medRxiv preprint service had examined infection rates and mask-wearing and found ample support for masks. Countries with societal norms or government policies supporting mask wearing had mortality increases of 8% in April and May, compared with 54% in the remaining countries, the observational study found.

Support for mask-wearing is not universal, but some critics are coming around. On Feb. 29, U.S. Surgeon General Dr. Jerome Adams tweeted that Americans should “STOP BUYING MASKS” because they don’t prevent people from catching the virus. As of Tuesday, Adams was tweeting in favor of wearing face coverings “to help protect yourself and others around you.”

President Donald Trump, one of the most prominent skeptics of masks in the U.S., last week changed his message and said he supported people wearing masks if they feel good about doing so. But on Monday, White House chief of staff Mark Meadows said on Fox News that a national masking mandate is not in the works.

The mask requirements in Minnesota cities bear broad similarities, but each is different in where, when and how it applies.

In Winona, Mayor Mark Peterson on Tuesday announced a 30-day citywide masking order that requires all residents and visitors to wear face coverings indoors in public buildings and “anywhere where physical distancing is difficult.” The city’s existing emergency declaration gave him the power to unilaterally impose the order, but the City Council can amend or end it at any point.

“The single most important action any Winonan can take to prevent the spread of COVID is to wear a mask,” Peterson said in a statement.

In Mankato, the City Council debated and ultimately passed an ordinance Monday night that lasts for 61 days and requires most people over the age of 12 to wear a mask in public indoors, and for employers to require public-facing employees to wear masks. The measure passed 5-2 after a two-hour debate.

Mankato Mayor Najwa Massad said in e-mail that she voted in favor as a member of the council: “After talking with our citizens that are in the medical field and getting their perspective, it was plain to me how we had to proceed.”

Mankato City Council Member Mark Frost voted against the ordinance, even after its proposed $1,000 fines were reduced to $200 for businesses, because of the skepticism he heard from Michael Osterholm, who Frost called the state’s top epidemiologist.

“He is the one who came out and just said they don’t work,” Frost said, because cloth masks “randomly allow air in, up the sides, or around your cheeks. … I would love to support this. But I think he’s right, that they’re not that great a deal.”

Osterholm, director of the University of Minnesota’s Center for Infectious Disease Research and Policy, has advocated social distancing as the most important risk-reduction tactic and said advocates of masks may be overselling the strength of their scientific evidence.

Even so, Osterholm supports wearing cloth masks, which are not harmful and can be beneficial, even if they don’t provide complete protection.