At least seven states have set new records for single-day increases in coronavirus cases, prompting some to set new restrictions as concerns mount over possible "superspreader events" during the upcoming holiday season.
Colorado, Idaho, Indiana, Minnesota, New Mexico, North Dakota and West Virginia all set records Friday in the number of new cases of the virus, NBC News' tally shows.
Colorado recorded 1,312 cases Friday, the same day Denver's mayor announced both a tougher mask mandate that requires residents to wear face coverings outdoors and a limit on gatherings in "unregulated settings" to no more than five people.
“Over the past several weeks, we have worked hard to reduce our caseloads and keep hospitalizations from increasing,” Mayor Michael Hancock said in a press release. “But we need to do more. With the holidays on the horizon, we must take these additional steps over the next 30 days and knuckle down together to do the hard work that needs to be done so we can all enjoy this upcoming holiday season.”
The mask mandate remains in effect until further notice, while the limit on gatherings is through Nov. 16.
Idaho recorded 1,094 new cases Friday, while Indiana and Minnesota each reported more than 2,200 cases, according to NBC's data.
The governor of Idaho, Brad Little, said Thursday that the state was going to stay in stage 4 of his reopening plan after having failed to meet the criteria for a full reopening for the ninth time in a row, the Idaho Statesman reported.
Little urged residents to continue wearing masks and practicing social distancing.
"Our personal actions work better to slow the spread of coronavirus than anything else,” the governor said, according to the outlet. “This is about personal responsibility, something Idaho is all about.”
Minnesota Health Commissioner Jan Malcolm said she was "very saddened" about the rise in cases, although she said some of it can be attributed to more testing.
“Some of the things that we maybe thought was O.K. to do a month or so ago is much, much riskier today just given this level of viral spread around our state,” she told MinnPost.
North Dakota and New Mexico also broke daily records Friday with 859 cases and 812, respectively. West Virginia and Wyoming each reported just under 500 new cases that day.
A spokeswoman for the New Mexico governor's office called the increase in that state a "Covid-19 wildfire," the Santa Fe New Mexican reported.
"The virus spreads when people give it the opportunity to spread, and New Mexicans are doing just that," spokeswoman Nora Meyers Sackett said.
In Wisconsin, health officials urged residents not to gather with anyone outside of their immediate families.
"I think people should think about all of the things that they're doing outside of the confines of their immediate families as a potential place that they could be coming into contact with Covid-19," said Andrea Palm, with the state's Department of Health Services. "Now is the time to make the choice not to do those things."
She added that community spread makes contact tracing difficult.
The rise in cases comes as the United States has surpassed 8 million infections and amid concern about what epidemiologists call a "third peak."
Many experts have also expressed concern that the holidays could trigger an increase in infections with gatherings of families and friends becoming "superspreader events."
Dr. Sadiya Khan, an epidemiologist at the Northwestern University Feinberg School of Medicine, told NBC News this week that as the weather gets colder more people will start to move gatherings indoors.
Dr. Carlos del Rio, an infectious disease expert at the Emory University School of Medicine, said there are "potentially six weeks of superspreader events" between Thanksgiving and New Year's.