By Susannah Cullinane, CNN

(CNN) -- Daily Covid-19 cases in the US reached a record high on Thursday, with experts warning that death rates could triple by mid-January.

There were 88,521 new cases of the coronavirus reported in the US on Thursday, according to data from Johns Hopkins University -- 9,540 more cases than Wednesday.

In total, there have been more than 8,947,980 cases and at least 228,677 deaths in the US -- 971 of them on Thursday, JHU data shows.

"This is the hardest point in this pandemic right now -- the next two months," Dr. Scott Gottlieb, former commissioner of the US Food and Drug Administration, said during an interview on CNBC's "Squawk Box" Thursday. "We can't give up our guard right now."

Thursday's average marks an 82.68% increase in new cases over the last month, Johns Hopkins says. This week alone, the nation added a record-setting 536,131 cases. Total coronavirus cases could top 9 million Friday.

On Thursday, nine states reported their record high single-day of new cases ever:, Johns Hopkins reported: Illinois, Indiana, Maine, Michigan, Minnesota, New Mexico, North Carolina, North Dakota and Ohio.

New Jersey Gov. Phil Murphy told CNN Friday that he attributed the rise in cases to the cold, "fatigue" and indoor private gatherings.

Murphy said he would consider a statewide curfew "if we had to," although he doesn't want it to come to that. In Newark, nonessential businesses must close at 8 p.m., among other restrictions.

Murphy announced 2,089 cases Friday, marking the state's highest one-day total since May.

Also Friday, Florida officials said the state had 5,592 more cases for a total of more than 800,000, according to the Florida Department of Health.

Only California and Texas have surpassed 800,000, according to Johns Hopkins data.

The Institute for Health Metrics and Evaluation at the University of Washington School of Medicine says it is most likely that by the middle of January, 2,250 Americans will be dying every day from the coronavirus -- three times more than the current rate.

And it could get much worse.

"If states do not react to rising numbers by re-imposing mandates, cumulative deaths could reach 514,000 by the same date," the IHME said in its latest forecast.

"The fall/winter surge should lead to a daily death toll that is approximately three times higher than now by mid-January. Hospital systems, particularly ICUs, are expected to be under extreme stress in December and January in 18 states."

And hospitals are already under increased strain. As of Thursday, more than 46,000 people were hospitalized, according to the Covid Tracking Project, with all but 11 states seeing a rise in hospitalizations this week.

States continue to break daily case count records

Forty-three states have shown an increase in cases compared to last week, with five holding steady and two -- Oklahoma and Louisiana -- reporting a decline, according to JHU.

New Mexico reported 1,082 cases Thursday -- a record -- and a top health care executive there sounded the alarm about the direction of Covid-19 spread in his state.

"We are at an unsustainable growth rate," said Dr. Jason Mitchell Thursday. Mitchell is the chief medical officer at Presbyterian Healthcare Services, which operates nine regional hospitals in New Mexico.

Mitchell says the state's rate of case growth is averaging about 5% a day, which would result in catastrophic numbers if there's no effort to change the trend. "By December, we would have so many cases that we would be in MASH tents," Mitchell said during a state health briefing.

Illinois also reported a daily high of new cases for the second time in a week with 6,363 new cases Thursday.

The total number of cases statewide now stands at 395,458, according to the Illinois Department of Public Health. Gov. J.B. Pritzker and IDPH announced that Region 3 would go into Covid-19 mitigation measures.

Nine of the state's 11 regions will now be under resurgence mitigation measures due to the high average positivity rates.

Minnesota, North Dakota and Ohio also reported their highest daily Covid-19 totals Thursday, with 2,872, 1,222 and 3,590 new positive cases respectively.

Officials warn against traditional get-togethers

The Oregon Health Authority reported 575 new cases Thursday, also breaking the state's single-day record.

"Preliminary data show this increase reflects continued widespread community transmission resulting in small clusters and outbreaks statewide," the OHA said in a written statement. The state's coronavirus death toll is now 673.

Health officials are strongly encouraging Oregonians to forgo traditional Halloween trick-or-treating and get-togethers this year.

Murphy said New Jersey was seeing a fall surge, as he announced another 1,477 cases Thursday.

Murphy urged residents not to take family members out of nursing homes for Thanksgiving.

"It's cold, it's rainy, our numbers are up. It gives me no joy to say you can't bring mom or dad out of the nursing home," Murphy said. "It gives me no joy to say you can't have your normal Thanksgiving."

Higher rates of Covid-19 after Trump campaign rallies

A CNN investigation of 17 Trump campaign rallies finds that 14 of the host counties had an increased rate of new Covid-19 cases one month after the rally.

The 17 rallies occurred between August 17 and September 26. CNN evaluated the rate of new daily cases per 100,000 residents at four weeks before the rally, on the rally date, and four weeks after the rally at the county level and at the state level.

Of the 14 host counties that had increased infection rates, eight of them had declining rates of infection in the month before the rally. The other six counties already had increasing rates of infection in that preceding month.

CNN's analysis also found that in 10 counties, the new rates of infection were growing faster than the overall rate for the state.

The investigation evaluated rallies in Minnesota, Wisconsin, Arizona, Pennsylvania, New Hampshire, North Carolina, Michigan, Nevada, Wisconsin, Minnesota, North Carolina, Ohio, and Florida.