CNN  — 

The US has marked a harrowing milestone: It recorded its highest one-day number of Covid-19 infections Friday at more than 83,000 – more than 6,000 higher than the country’s previous record set in July.

And as the fall surge continues, the daily numbers will get worse, experts warn.

“We easily will hit six-figure numbers in terms of the number of cases,” Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota, told CNN Friday night. “And the deaths are going to go up precipitously in the next three to four weeks, following usually new cases by about two to three weeks.”

This comes as the country’s seven-day average of new daily cases surpassed 63,000 Friday – an 84% increase since the average started ticking back up in mid-September, according to Johns Hopkins University data.

So far Saturday, Johns Hopkins reported 55,537 new cases and 562 deaths across the nation. At least 8,547,198 cases and 224,537 deaths have been reported this year.

Health officials say the steep inclines follow the reopening of schools and colleges across the US and have been largely driven by small gatherings – often family events – that are increasingly moving indoors, where the virus is likely to spread.

In Maryland, the governor said this week family gatherings were the No. 1 source of transmission in the state, followed by house parties. In North Carolina, health officials reported its highest daily case count Friday and said they continue to see clusters “from social and religious gatherings.”

Unlike many European countries that are also experiencing spikes, the US never lowered its daily case baseline very far, meaning the compounding of cases could be worse, experts say.

And that’s ahead of several popular holidays, when health officials worry more Americans could let their guard down and opt to visit family and friends and further drive surges.

In North Dakota, with the highest per capita new case rate in the country, Gov. Doug Burgum called for a “Thanksgiving challenge,” urging residents to follow mitigation guidance like masks and social distancing to bring numbers down by the holiday.

“It would be really great to be sharing with all of you at Thanksgiving that our numbers are going down as we head into the holiday period,” he said Friday. “That we’ve got increasing amounts of hospital capacity. That our schools have remained open, that our businesses are open during that holiday season.”

At least 35 states report rise in cases

The Florida Department of Health on Sunday reported 2,385 additional coronavirus cases and 12 new resident deaths.

At least 34 states reported more new Covid-19 cases in the last week than the week prior, according to Johns Hopkins data. In Georgia, health officials reported their highest one-day case count Friday since early September. Ohio health officials reported a record-high of daily new cases for the third day in a row, and in Oklahoma, officials reported more than 1,000 new infections for the fourth consecutive day.

New Jersey Gov. Phil Murphy on Saturday reported an additional 1,994 coronavirus cases – the highest single-day total since May.

“We’re still in the midst of a pandemic and need everyone to take this seriously. Wear a mask. Social distance,” Murphy tweeted.

New Jersey had eight new virus-related deaths, bringing the state’s total fatality toll to 14,492.

“This virus has not gone away simply because we are tired of it,” Murphy said.

In Florida, health officials on Saturday reported 4,471 additional cases and 77 new resident deaths. That’s the third day this month the state has reported more than 4,000 new cases in a single day, according to a CNN tally.

Pennsylvania reported 2,043 new cases Saturday.

Pennsylvania, as of Saturday, saw 2,043 new cases, bringing the statewide total to 192,622.

“Daily increases are now comparable with what we saw in April 2020,” the state health department said in a statement. An additional 29 virus-related deaths were reported Saturday.

Michigan, with 3,338 new cases Saturday, marked its highest single-day total during the pandemic, according to state Department of Health and Human Services spokeswoman Lynn Sutfin. The state also reported 35 new deaths.

Dr. Joneigh Khaldun, Michigan’s chief medical executive and chief deputy for health, said the data showed “alarming increases” in new infections.

“If rates continue like this, we risk overwhelming our hospitals and having many more Michiganders die,” Khaldun said in a statement.

And more than 41,000 Covid-19 patients were in US hospitals Friday, according to the Covid Tracking Project. In Illinois, the number of hospitalized Covid-19 patients increased by at least 17% over the last week, the governor said Friday.

The Texas Division of Emergency Management is establishing an alternate care site in El Paso to expand hospital capacity, according to Gov. Greg Abbott’s office. The facility will open Monday and provide additional beds, equipment and personnel.

Illinois Public Health Director Dr. Ngozi Ezike made an emotional appeal to residents on the importance of face coverings.

“As we see the numbers go up in the hospitals, people are bringing more beds, trying to prepare for the Covid units again. And these staff that went through all that pain to try to save as many people as they can are seeing history repeat itself,” she said. “We don’t have a vaccine yet, but we have a mask, and we’re asking people to use that, and I don’t know what else we can say.”

In Tennessee, hospital officials said new cases in metro Nashville have increased 50% in the last two weeks, and hospitals in the area saw a 40% increase in patients over the same time period.

And Colorado officials issued a new order limiting gatherings to 10 people from no more than two households in response to climbing infections and hospitalizations.

“We need to keep gatherings smaller and with people from fewer households — we are asking everyone to ‘shrink their bubble’ to reduce the spread,” Colorado Department of Health and Environment Executive Director Jill Hunsaker Ryan said in a Friday news release.

‘This is not a drill’

Despite the troubling trends, health officials maintain basic public health measures can help turn things around: masks, social distancing, avoiding crowds and frequent hand washing.

“They sound very simple, but we’re not uniformly doing that and that’s one of the reasons why we’re seeing these surges,” Dr. Anthony Fauci said Friday. “We can control them without shutting down the country.”

A new modeling study from the forecasting team at the University of Washington’s Institute for Health Metrics and Evaluation shows if 95% of Americans wore masks in public, more than 100,000 lives could be saved through February.

But despite the forecast and experts’ warnings, face coverings remain a point of contention across the US. It just might be time for the country to mandate mask use, Fauci said.

“I think that would be a great idea to have everybody do it uniformly,” he said. “If people are not wearing masks, then maybe we should be mandating it,” he said.

A leading World Health Organization official on Friday also urged country leaders to “take immediate action to prevent further unnecessary deaths, essential health services from collapsing and schools shutting again.”

“As I said it in February and I’m repeating it today, this is not a drill,” WHO Director-General Tedros Adhanom Ghebreyesus said in a news conference.

Fauci: Widespread vaccination not possible until 2021

While many experts and officials have worked to give hopeful estimates on when a Covid-19 will be available, that timeline remains uncertain.

National Institutes of Health Director Dr. Francis Collins said Friday that while he’s “cautiously optimistic” about the US having a vaccine authorized by the end of the year, he said it “might not happen and it might take longer.”

But Collins added it was good news that the US has more than one vaccine candidate in development.

“If you were betting the whole thing on one vaccine, I’d be a lot more worried,” he said.

His remarks came the same day drugmakers AstraZeneca and Johnson & Johnson announced they were set to resume their paused Covid-19 vaccine trials in the US, both of which saw health scares in participants.

And when a vaccine does get approved, experts have said it’s crucial that enough Americans get it. If only half of the country is willing to get vaccinated, Collins warned, Covid-19 could stick around for years.

“When I look at the attitudes that are out there now about this vaccine, and about who would be interested in taking it – it’s really, really troubling,” Collins said at a National Press Club virtual event. “I’ve been talking so optimistically about how we are likely to have a vaccine by the end of the year, but if only 50% of Americans are interested in taking it, we’re never going to get to that point of immunity across the population where Covid-19 goes away.

CNN’s Alec Snyder, Melissa Alonso,. Brad Parks, Hollie Silverman, Ganesh Setty, Alta Spells, Shelby Lin Erdman, Gisela Crespo, Naomi Thomas and Jacqueline Howard contributed to this report.