Covid-19 Live News and Updates

California’s intensive care units could be overloaded by the middle of December, and its hospitals could be dangerously close to full by Christmas, according to sobering projections that Gov. Gavin Newsom presented on Monday.

And the strain could be even worse in the hardest-hit areas, like the San Joaquin Valley, which was projected to reach 83 percent of its hospital capacity by Dec. 24.

“If these trends continue, California will need to take drastic action,” Mr. Newsom said during a virtual briefing, adding that more severe restrictions, including full stay-at-home orders, could come within the next few days.

California is one of several states that had appeared to have gained control of the virus, only to see it spread rapidly throughout the fall. On Sunday it became the first state to record over 100,000 cases in just a week, according to a New York Times database.

A University of Arizona Covid-19 modeling team recently urged the state of Arizona to take action to stem hospitalizations or else “risk a catastrophe on a scale of the worst natural disaster the state has ever experienced.”

And in New York, Gov. Andrew M. Cuomo said the state will take a series of emergency actions as it faces a new “nightmare of overwhelmed hospitals.”

Already, 99 percent of California’s residents are under a curfew that bans them from leaving their homes to gather or to go to nonessential businesses after 10 p.m. Los Angeles County health leaders have gone even further, announcing a ban on all gatherings in public or at private homes that goes into effect on Monday.

The surge has upended some marquee elements of California’s sports scenes. The San Francisco 49ers will play their next two home games in Glendale, Ariz., after health officials in Santa Clara County, Calif., where the team’s stadium is, banned contact sports at all levels through late December in a bid to slow the surge in virus infections there. The U.C.L.A. men’s basketball team announced that its home opener, scheduled for Monday, was being postponed because of its opponent’s virus protocol.

Officials had spent the weekend talking with local leaders and health care providers about their concerns, said Dr. Mark Ghaly, the state’s secretary of health and human services, who also spoke during the Monday briefing.

“Everything is on the table, in terms of how we guide the state through this,” he said. “And we want to make sure what we do is impactful and as time-limited as possible.”

But unlike early in the pandemic, when just a few coastal states bore the brunt, the governor noted that the tidal wave of cases slamming the entire country has limited the likelihood of aid from the federal government or other states.

The total number of coronavirus cases in the United States for November surpassed four million on Saturday, more than double the record set in October of 1.9 million cases. And…