Officials across the U.S. urge Americans to change their behavior as the pandemic accelerates.

As the United States shatters record after record on coronavirus cases and hospitalizations, more warnings emerged from officials across the country urging residents to adjust their behavior and prepare for more possible changes on the horizon.

On the West Coast, the governors of California, Oregon and Washington urged their residents on Friday to avoid all nonessential interstate travel in the days ahead, joining their counterparts across the country in pleading with residents to take precautions.

In New York City, an early hot spot now facing a possible second wave, the mayor warned on Friday that public schools could close as early as Monday as the seven-day average positivity rate jumps. Private residential gatherings must be limited to 10 people beginning at 10 p.m.

In a joint statement, Gov. Gavin Newsom of California, Gov. Kate Brown of Oregon and Gov. Jay Inslee of Washington also pushed people to limit interactions to their immediate households and stay local, and for incoming travelers to quarantine for 14 days upon arrival.

“As hospitals across the West are stretched to capacity, we must take steps to ensure travelers are not bringing this disease home with them,” Ms. Brown said in the statement. “If you do not need to travel, you shouldn’t. This will be hard, especially with Thanksgiving around the corner. But the best way to keep your family safe is to stay close to home.”

Nearly half of the states have measures in place for visitors, but the measures themselves from mandatory testing to quarantine requirements. On Thursday, California surpassed one million cases, becoming the second state, after Texas, to do so.

But while the virus is worsening on the coasts, it is accelerating at an even more alarming clip in the center of the country, stretching medical resources to the breaking point and prompting states, counties and cities to consider economically devastating lockdowns.

The latest wave of cases is washing over nearly every part of the United States, unlike the spring, when it was concentrated in the New York metropolitan area. Case numbers are trending upward in 46 states, and no states are seeing declines. More than 30 states, from Alaska to New Hampshire, have set records in recent days.

On Thursday, public health officials recorded more than 150,000 new cases in a day for the first time — more than 160,000, in fact. That has pushed the seven-day average of new daily cases to more than 134,000, as of Thursday, an increase of 72 percent from the average two weeks earlier.

It was only eight days earlier that the country had its first 100,000-case day. Six of the last nine days have set records...

Hospitalizations for Covid-19 also set a national record on Thursday for the third-straight day, reaching 67,096, according to the Covid Tracking Project. That figure has doubled in just five weeks. ...