Edina is one of the cities requiring face masks to be worn in public places to mitigate transmission of the coronavirus. The city’s order went into effect on Monday. Here, the 50th & France shopping district in late June. (The Minnesota Star Tribune)

What's the difference between Winona and Red Wing? Or between Edina and Richfield? While these cities have their defining characteristics, a newcomer to Minnesota might have trouble telling them apart.

Lately, though, there's a distinction that's as plain as the nose on your face: In response to the COVID-19 pandemic, Winona and Edina require people to wear masks in public places. Red Wing and Richfield do not.

In the absence of a uniform state policy requiring masks — better yet, a national mandate — cities, businesses and other smaller jurisdictions are on their own. As public-health policy goes, it's perverse, because it imagines that the novel coronavirus somehow respects political borders. Also because it supposes that mayors, city councils or business owners have an expertise that public-health practitioners lack. Also because a patchwork of different regulations is difficult for ordinary people to navigate.

But the most confounding result of this failure of public policy is that it leaves some of the enforcement in the hands of those who are least able to enforce: merchants, cashiers, bartenders and the like. A small-business owner is probably already suffering economic hardship as a result of the pandemic; is that business owner now supposed to alienate customers by requiring that they wear a mask while on the premises?

Nor is a loss of customers the worst possible outcome. All over the country, anti-mask zealots have expressed their antipathy by shouting, punching or shoving those who ask them to cover their faces. People have been hurt.

Some of those who object to wearing masks sound a bit like motorcycle riders who won't wear helmets: They claim it's a matter of personal choice. That argument fails because it misconstrues the purpose of the mask. It is not like a helmet. It is there to protect not the wearer, but everybody else.

These numbers should be convincing: The University of Washington's Institute for Health Metrics and Evaluation (IHME) projects that 45,000 fewer Americans will die from COVID-19 by Nov. 1 if mask wearing is "universal."

By now, there has been enough effort at public education that people shouldn't need an executive order to motivate them to wear masks. The facts are these: Wearing a cloth mask offers some, but not perfect, protection against transmitting COVID-19. Masks alone are not enough, but they help. They also serve to remind everyone who sees them that we are still in a public-health emergency, and that everyone must do their part.

That means, among other things, avoiding crowds, especially indoors. If you find yourself in a crowd, keep at least 6 feet from those around you. Wash your hands frequently with soap and water; use hand sanitizer when soap and water are hard to come by. Try not to touch your face.

And anytime you are around people, or in a place where people have been present or are likely to be, wear a mask. Make sure that you are wearing it properly, covering your nose as well as your mouth, and that it fits snugly on your face. If it is a reusable cloth mask, wash it every day. Masks of several layers are probably most effective.

Society has not been well served by the lack of consensus on how to respond to COVID-19. Ever since President Donald Trump remarked, "I don't think I'm going to be doing it … . I don't see it for myself," the wisdom of wearing a mask has been treated as a matter of opinion. Until we have a vaccine, our best defense is a united front, with clearly understood standards for everyone to follow.

Our recommendation is that Gov. Tim Walz declare a statewide mandate that masks be worn in Minnesota's public places. The sooner the better.