(CNN) — As coronavirus cases make a massive surge in many states, Americans head into this Fourth of July weekend facing increased restrictions on traditional activities like going to the beach, joining friends at a bar and flocking to watch fireworks.

Los Angeles County and surrounding communities closed beaches over the weekend as California approached a quarter million reported cases of Covid-19.

“We cannot risk having crowds at the beach this holiday weekend,” Janice Hahn, a member of the Los Angeles County Board of Supervisors, said in a tweet.

In hard-hit South Florida, beaches from Palm Beach to Key West will be shut down for the holiday weekend. The city of Key West explained why: “To avoid large crowds gathering during this Covid-19 pandemic.”

One hopeful note from the other end of the country: New York City beaches have opened for swimming.

Meanwhile, Laguna Beach in Orange County, California, canceled the city’s annual fireworks display. “Sorry for the bad news but it’s for the best this year,” city police department spokesperson Jim Cota said.

While other cities canceled fireworks to keep people from crowding together, places like Los Alamitos and Seal Beach, California, got creative. They’re jointly holding a “Drive-Up 4th of July Fireworks Spectacular” that bans pedestrians and includes temperature checks.

Nineteen states have changed or paused reopening plans because of spikes in coronavirus cases, and bars have come in for particular attention.

Texas Gov. Greg Abbott closed most bars closed a few days ago, saying they contributed to the alarming spike in cases in the state.

California Gov. Gavin Newsom has ordered bars in seven counties to close over the weekend and said he will announce more restrictions on Wednesday.

Colorado shut down bars and nightclubs and Delaware Gov. John Carney closed bars at state beaches ahead of the weekend.

Dr. Anthony Fauci, the director of the National Institute for Allergy and Infectious Diseases, gave bars nothing to cheer when he appeared before Congress this week.

“Bars: really not good, really not good. Congregation at a bar, inside, is bad news. We really have got to stop that,” Fauci said Tuesday.

Fauci says 100,000 case a day possible

Fauci offered a bleak warning in his testimony: Americans need to take sensible measures to curb the spread or risk seeing 100,000 new cases a day.

“We are now having 40,000 cases a day. I would not be surprised if we go up to 100,000 a day if this does not turn around,” he told the Senate Health, Education, Labor and Pensions (HELP) Committee hearing.

Turning it around will take a coordinated, collaborative effort, he said at the hearing, not the “disparate responses” the nation has shown so far.

But without strong national leadership, that coordination may be up to mayors and governors, according to Dr. William Haseltine, a former biotechnology executive and professor at Harvard’s medical and public health schools.

“This situation is now so grim and is getting worse by the day,” he said. “From now on, they know it’s in their backyard and their job to take care of it if no one else does.”

Most of the US has the pandemic in their backyard, with only two states — New Jersey and Rhode Island — showing a downward trend in cases from last week. The surge comes as restriction-fatigued Americans increasingly gather in large groups for summer recreation.

Precautions like social distancing and mask wearing are meant to help people “enjoy themselves within the safe guidelines,” Fauci said.

“We should not look at the public health endeavors as being an obstruction to opening up. We should look at it as a vehicle to opening up,” he said.

Turning the tide means more masks and fewer bars

The measures health experts tout to curb the virus are especially important considering more than 90% of the country has not experienced the virus.

That means so-called herd immunity could still be years away, Dr. Robert Redfield, director of the US Centers for Disease Control and Prevention (CDC), told the Senate HELP committee Tuesday.

Both Redfield and Fauci stressed the importance of widespread masks, which experts have encouraged for months even as President Donald Trump has noticeably forgone them.

An environment with universal masks is “fundamentally the most important thing we can do,” Redfield said.

California and Florida chart different coronavirus paths

Officials in California and Florida — two states where coronavirus cases are jumping — are taking different approaches toward reopening amid spikes in infections.

Florida Gov. Ron DeSantis told the reporters that there’s no going back to stricter measures, while Gov. Newsom in California hinted that on Wednesday he’ll tighten restrictions this Independence Day weekend, especially at beaches.

As the holiday weekend looms, Newsom warned that family gatherings — where households tend to let down their guards mixing with extended family — are the greatest concern.

“It’s not just bars, not just out in the streets with people protesting, and the like,” Newsom said.

Newsom ordered bars in seven counties to close over the weekend and said he will announce more restrictions on Wednesday.

Newsom has repeatedly promised that reopening the state comes with the ability to “toggle back” if necessary.

Responding to a reporter’s question about the beaches being closed in Los Angeles County for the Independence Day weekend, the governor hinted that state beaches could be part of his announcement.

In Florida, DeSantis assured reporters that his state can deal with the uptick in cases and it’s not necessary to shut down shops and restaurants.

“We’re not going back, closing things,” he said. “I mean, people going to business is not what’s driving it.”

DeSantis’ message to Floridians, particularly the younger ones: Protect the vulnerable.

“You have a responsibility not to come into close contact with folks who could be more vulnerable,” he said.

Many cases are undetected

Cases in Florida have increased more than 50% from last week, and experts have warned the state could become the next epicenter, similar to New York in the spring.

But DeSantis said he rejected experts’ predictions, adding that the state can handle whatever comes.

“People were predicting you know 400,000 people hospitalized, never came,” he told CNN’s Randi Kaye. While cases are rising, he said that the percentage of tests coming back positive is still “low” at 10% to 15%.

But a former commissioner of the US Food and Drug Administration, Dr. Mark McClellan, said Tuesday that the real case numbers may be higher than reported — and the number of new cases may already be at 100,000 per day because many people haven’t been tested.

“It just really emphasizes the importance of taking further steps, on wearing masks, on pausing reopening, on taking steps ahead of July 4th to avoid big crowds,” McClellan said.

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