CHICAGO — Restaurants, schools, movie theaters and bars are reopening and shedding restrictions in some of the nation’s biggest cities and most populous states, prompting more Americans to emerge after months of isolation and bringing the country closer to a semblance of life before the coronavirus pandemic.

In Chicago, tens of thousands of children returned to public school this week, while snow-covered parks and playgrounds around the city that have been shuttered since last March were opened. Texas ended its mask mandate and erased pandemic-related restrictions on businesses. Restaurants in Massachusetts were allowed to operate without capacity limits, and South Carolina erased its limits on large gatherings.

The reopenings were seen as both an official encouragement of a return to public life and also a reflection of the hope that the country is starting to feel as vaccines roll out and virus cases drop.

But many Americans are left in a quandary: wondering whether to follow the lure of optimism, as governors and mayors in California, Michigan and North Carolina endorsed widespread reopenings of businesses and schools, or to heed their own lingering concerns about the virus and the warnings of federal health officials who have said it is premature to lift too many restrictions.

As Kitty Sherry, 36, sent her son, Jude, off to his Chicago elementary school this week for the first time in nearly a year, she felt caught in a middle ground between elation and worry.

“There’s a part of me that’s really excited that he’s back in school,” Ms. Sherry said. But she said she worried about the health risk to teachers, and said her family was still avoiding restaurants and other indoor spaces because of the pandemic. “It’s not over yet,” she said. “So there’s not too much celebrating.”

Government officials have sent mixed, often cautious messages to the public. Dr. Anthony S. Fauci, President Biden’s chief medical adviser for Covid-19, said this week that for small groups of people who have all been fully vaccinated, there was low risk in gathering together at home. Activities beyond that, he said, would depend on data, modeling and “good clinical common sense,” adding that the Centers for Disease Control and Prevention would soon have guidance for what vaccinated people could do safely.

The director of the C.D.C., Dr. Rochelle Walensky, said during the same briefing on Monday that she was “really worried” about the rollbacks of restrictions in some states. She cautioned that with a decline in cases stalling and with variants spreading in cities like New York, “we stand to completely lose the hard-earned ground we have gained.”

“I know people are tired; they want to get back to life, to normal,” Dr. Walensky said. “But we’re not there yet.”

The message that many Americans are hearing from their elected officials is more cheery.

Gov. Gretchen Whitmer of Michigan said on Tuesday that she was easing restrictions on businesses and allowing family members who have tested negative for the coronavirus to visit nursing home residents.

In Kentucky, all but a handful of school districts are now offering in-person classes, while the state races to vaccinate teachers as quickly as possible. Gov. Andy Beshear told reporters last week that the state’s falling infection statistics showed that immunizations were beginning to make an impact.

“It means vaccinations work,” he said. “We’re already seeing it. We’re seeing it in these numbers. It’s a really positive sign.”

There are plenty of reasons for optimism: Vaccinations have increased significantly in recent weeks, and daily reports of new coronavirus cases have fallen across the country from their January peaks.

The positive signs come with caveats. Though national statistics have improved drastically since January, they have plateaued in the last week or so, and the United States is still reporting more than 65,000 new cases a day on average — comparable to the peak of last summer’s surge, according to a New York Times database. The country is averaging more than 2,000 deaths per day, though deaths are a lagging indicator because it can take weeks after being infected with the coronavirus to die from it.

New, more contagious variants of the virus are circulating in the country, with the potential to push case counts upward again. Testing has fallen 30 percent in recent weeks, leaving experts worried about how quickly new outbreaks will be known. And millions of Americans are still waiting to be vaccinated — including workers in restaurants, which are now open in vast numbers across the country.

In states like Florida and South Dakota, schools and businesses have been widely open for months, and many local and state officials across the country have been easing restrictions since last summer. Still, the pace of reopenings has quickened considerably in the last few days.

“We’re, hopefully, in between what I hope will be the last big wave, and the beginning of the period where I hope Covid will become very uncommon,” said Robert Horsburgh, an epidemiologist at the Boston University School of Public Health. “But we don’t know that. I’ve been advocating for us to just hang tight for four to six more weeks.”

Jennifer Nuzzo, an epidemiologist at the Johns Hopkins Center for Health Security, said that there are signs that the country may be through the worst of the pandemic. But she is still worried that states are reopening too hastily, repeating the same mistakes made in earlier periods of the pandemic when loosened restrictions were followed by new spikes in cases.

“Rather than opening a few lower-risk things and seeing just to make sure it doesn’t change the numbers, it just feels like they’re just kind of opening the floodgates,” Dr. Nuzzo said.

Most schools across the country are open to students, at least partially in person, and evidence suggests they have done so relatively safely. But school reopenings for some districts have been delayed repeatedly by outbreaks in communities where other types of restrictions remain lifted.

“My son is due at the end of the week to attend hybrid learning for the first time,” said Dr. Nuzzo, who lives in Maryland. “Meanwhile, the restaurant restrictions have been lifted, the movie theaters are coming back, and it just feels like, let him at least get into the classroom first.”

In South Carolina, officials this week lifted a rule requiring restaurants to close by 11 p.m., and in North Carolina, bars were allowed to open indoors at limited capacity over the past weekend for the first time since last March.

Last year’s shutdown forced Zack Medford, 38, to abruptly close the five bars he owned in North Carolina, lay off 80 employees, and apply for unemployment benefits. He has had to give up two of his bars after falling behind on rent payments while they sat empty.

But on Wednesday, the state announced that bars could open Friday at 30 percent of their indoor capacity. With two days’ notice to reopen, he called old employees, who were eager to return to work, and restocked the inventory. Then on Friday, he opened his doors and welcomed back regular customers he had not seen in a year to have a drink at the bar.

“It was an exhilarating feeling to see that happen,” said Mr. Medford, who is also the president of the state’s bar and tavern association. “It really was the first time in a year that I got out of bed and was excited, had something to look forward to.”

After some counties in Washington State allowed movie theaters to reopen, Nick Butcher, 36, made up for lost time by attending screenings of the “Lord of the Rings” trilogy for three straight nights. He bought M&M’s at the concession stand, sat distanced from others in the audience, and said he felt as though things were almost back to normal.

“I’m actually getting optimistic, over all,” said Mr. Butcher, a software engineer at Microsoft who recently recovered from a case of Covid-19, as did several relatives. “This week is one of the first times I’ve gone into my office almost since the pandemic started.”

A return to crowded office spaces and schools left other Americans both elated and unsettled.

Amanda Sewell, a teacher at Tates Creek High School in Lexington, Ky., will welcome students to her classroom next Monday for the first time in a year. Decorations from last year’s Mardi Gras celebration still hang in the class. The date on her whiteboard still reads March 13, 2020 — the day school closed and she went home, feeling certain it would just take a couple of weeks before she and her students were back in the classroom.

Ms. Sewell is fully vaccinated against the virus now, and said she is thrilled to see her students in person after teaching to unresponsive squares on Zoom for months. But she knows things will not be the same as before.

“I’m still a little leery in that I feel like some people feel like because we have a vaccine that the pandemic is over, and its definitely not,” Ms. Sewell said. “I feel like we’re still several months out from being anywhere close to where normal was.”

Julie Bosman reported from Chicago, and Lucy Tompkins from New York. Dave Montgomery contributed reporting from Austin, Texas.