At least 1,343,167 new Covid infections were identified Monday, according to the tally, beating the previous record of 1,044,970 cases, set on Jan. 3, by nearly 300,000.
Daily case counts are typically high on Mondays because many states do not report the numbers over the weekend. However, the number still suggests a dramatic rise in cases in the U.S. as the highly transmissible omicron variant continues to spread.
It also represents the highest daily total recorded for any country, according to Reuters, with the U.S. recording a total of 61,490,917 cases since the pandemic began, as of Monday, according to NBC News' data.
The seven-day average for cases in the U.S. also reached its highest point yet Monday, hitting an average of 740,594 cases per day, with 24 states reporting their highest seven-day average ever.
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The record numbers came as Covid hospitalizations in the U.S. also soared, with the seven-day average for hospitalizations reaching 135,574 on Monday, up 83.1 percent in the last two weeks.
The surge in hospitalizations has been particularly noticeable in some Midwestern and mid-Atlantic states, according to an NBC News analysis of U.S. Department of Health and Human Services Covid hospitalizations data.
As of Monday, the population-adjusted rate for Washington, D.C., was the highest in the nation, followed by New Jersey, New York and Ohio.
Meanwhile, Southern states have seen the largest shift in hospitalizations over the past two weeks, with the seven-day averages for hospitalizations in Louisiana up 341 percent, from 340 to 1,501 over the past two weeks, while Florida has seen its average soar by 277 percent, from 2,426 to 9,169, according to NBC News' tally.
As the highly contagious omicron variant spreads, hospitals have also reported a growing trend of patients admitted for other ailments also testing positive for Covid-19.
Doctors told NBC News the trend could mean more people are having asymptomatic or undiagnosed cases than the current data shows.
In its weekly review on Covid published on Friday, the Centers for Disease Control and Prevention said cases across the country were continuing to "increase rapidly," with the surge "driven by the omicron variant."
The health body said that CDC projections suggested the omicron variant may now account for approximately 95 percent of Covid cases in the U.S.
"The entire country is now experiencing high levels of community transmission," it said, noting that "hospitalizations are also on the rise."
"While early data suggest omicron infections might be less severe than those of other variants, the increases in cases and hospitalizations are expected to stress the healthcare system in the coming weeks," it warned.