Anticipation and Anxiety Build Ahead of the Total Solar Eclipse

Millions of people will tilt their heads skyward on Monday, marveling at a total solar eclipse. The moon will cross the sun and block its light for a few fleeting moments, creating a communal celestial experience that will not again be so accessible to people in the United States, Canada or Mexico for decades.

The total solar eclipse’s path — the expanse where the moon fully obscures the sun — stretches from Mexico’s Pacific Coast to the fringes of Atlantic Canada, passing through dozens of major cities where authorities are preparing for an influx of visitors eager to experience what may be a once-in-a-lifetime opportunity.

In New York, signs along the Thruway urged travelers to “Arrive Early, Stay Late” to avoid the inevitable jams that will clog routes to and from prime viewing areas along the eclipse’s path.

Closer to Niagara Falls, which is in the path of totality, the second half of the message switched to a more realistic “Expect Delays.”

It will be the first total solar eclipse visible from the United States since 2017, and there will not be another visible in the lower 48 states until 2044. On Monday, much of the country is expected to take in the view. In 2017, a majority of American adults watched the eclipse in person, according to an estimate by Jon D. Miller, a research scientist at the University of Michigan. The figure, 154 million, is far beyond the audience of even the most-watched Super Bowl (123.4 million this year). And the path of totality for Monday’s eclipse crosses over more than twice the number of people as did the 2017 event.

Many eclipse-gazers are anxiously checking the weather forecast for Monday. National Weather Service forecasters on Sunday morning said that nearly everyone along the path in the United States will have at least some chance of clouds obscuring their view.

Forecasters said there was a high likelihood of clouds in Central Texas, and had a growing concern about severe storms across much of the state. They saw grounds for optimism in Little Rock, Ark., and the outlook for Cleveland was improving. But from there to Buffalo much remains uncertain, and the picture may not become clearer until hours before the eclipse.

One exception was Maine, where the agency’s forecaster said that people in the state had “scored a nearly perfect day” to view the eclipse.

Cities across the country have canceled school, and millions of protective glasses are being distributed or sold. Scientists have warned people never to look directly at the sun without protective eyewear because serious retinal injuries can occur.

Across North America, there are a wealth of planned special events, including street parties in Mexico, a study of animals at an Indianapolis zoo and an eclipse display at Niagara Falls.

In Mazatlán, the coastal Mexican city that will be one of the first places where people can see the eclipse from land, the seaside promenade is teeming with tourists.

Authorities there said that they were expecting about 120,000 people. The few hotel rooms available were going for triple or quadruple normal rates.

“This is where the eclipse hits land,” said Greg Schmidt, the director of NASA’s Solar System Exploration Research Virtual Institute, who is with a team that will livestream the eclipse from the city.

Mr. Schmidt selected Mazatlán about two years ago as his team’s eclipse site. He sounded sanguine about the choice compared with other places along the eclipse’s path; weather forecasts were favorable for high cirrus clouds.

“We should at least be able to see totality through that,” he said, contrasting Mazatlán with Texas, which, he said, “is now showing a lot of problems weather-wise.”

In Dallas, more than a thousand miles away from Mazatlán, many people were already resigning themselves to not being able to see the eclipse.

Eric Isaacs, the president of the Carnegie Institution for Science in Washington, D.C., which was hosting a three-day feast of science and sightseeing in Dallas for donors and friends of the institution, said the group’s viewing location had already been shifted to a mansion where people would be able to gather inside if they needed to get out of the rain.

Much farther north and east, a black inflatable planetarium in the cafeteria of the College of the North Atlantic gave a long queue of residents of Gander, Newfoundland, a preview of what they hope to see on Monday.

The community, which sheltered trans-Atlantic air travelers whose planes were diverted after the Sept. 11 terrorist attacks, is the near the end of the eclipse’s path but may have to settle for the simulation. A meteorologist with the Canadian weather service told The Canadian Press on Friday that cloud cover will make viewing totality in Gander “a writeoff.”

In Buffalo, Martin Penkala, 60, an aide at the Buffalo Psychiatric Center and an amateur astronomer, wouldn’t let a gloomy weather forecast interfere with his excitement.

“We will still see the total darkening for three minutes,” he said at an eclipse-inspired concert at the Buffalo Philharmonic on Saturday night. “That will be stupendous!”

In Canada’s Niagara region, authorities declared a state of emergency 10 days before the event, allowing officials to expedite safety and police resources if needed.

The emergency declaration added to the mild sense of panic that has settled over Niagara Falls and several large cities in Ontario within a two-hour drive, including Hamilton and Toronto.

But in other parts of the eclipse path, signs of gridlock had yet to materialize on Sunday afternoon. Those areas included the long, lonely stretch of Interstate 95 in Maine between Bangor and Houlton, the last town in the United States that will experience totality on Monday.

At Marden’s, a department store just outside downtown Houlton, Paul Kinney, 71, said he had seen few out-of-state cars so far, and expected the influx to be limited by the availability of hotel rooms.

“I’m expecting hundreds, not thousands,” he said.

But across the parking lot at the state visitors center, there were signs of building crowds.

Abhi Hazra, an Atlanta resident, had booked plane tickets to Mexico for the eclipse. But as forecasts evolved, and the chance of sunny southern skies turned uncertain, Mr. Hazra and his friends scrapped their plans and struck out in search of better weather. They flew to Boston, drove to Quebec, and booked a hotel there; when clouds threatened in Canada, they retreated back to Maine.

“The chance of clouds here tomorrow is 14 percent — so this place wins,” he said.

In New York State, Jessica DeCerce, the governor’s director of interagency operations, said officials were preparing for the eclipse as they would for a weather catastrophe. The total eclipse will be visible across a wide swath of the state. New York City is outside the path of totality, but it will experience about a 90 percent eclipse around 3:25 p.m. Eastern.

Ms. DeCerce has been nicknamed the state’s Eclipse Czar and has been spending the last two years thinking of everything that could go wrong: traffic gridlock, a lack of bathrooms, shaky cellphone service.

She did not want to name one spot she thought would be best to view the eclipse, but she said it would be difficult to beat Niagara Falls.

“Can you imagine a better place to watch this than in front of one of the world’s natural wonders?” she said.

While Monday may be the first and only time some people see an eclipse, others, like Marian Garrigan, who traveled south to Carbondale, Ill., from Chicago, were excited for a second opportunity.

She last visited the town in 2017 to see her first total solar eclipse, which she said was “awesome.”

Carbondale is home to Southern Illinois University, where Ms. Garrigan attended college in the 1970s. During the 2017 eclipse, she reunited with two of her college roommates.

“The eclipse gave us this perfect excuse to be here,” she said.

To celebrate their 70th birthdays, they’re getting together again for this eclipse.

A second eclipse was also on the mind of another 70-year-old woman, Gladis Mejía Roa, on Isla María Madre, an island off the coast of Mexico.

Ms. Mejía Roa remembered seeing an eclipse in 1991 and to do it a second time, she said outside the island’s church, “is a fortune to me.” It may likely be her last chance. Mexico will not witness another total solar eclipse until 2052.

“And you know what? I don’t think I want to see that one,” she added and laughed.

In Indianapolis, officials at the city’s zoo plan to distribute as many as 10,000 pairs of eclipse glasses to visitors and have ensured that the zoo’s automatic lights will not turn on when the sky darkens.

Alicia Bonanno, an operations coordinator in charge of several parts of the zoo, said she couldn’t wait to find out how the macaws would react to the eclipse.

“The disturbance in air pressure might cause them to fly around because they feel like it’s going to storm,” she said, as the birds squawked in the enclosure in front of her. But there was another possibility. “They could just tuck in for the night. We’ll just have to see.”

Reporting was contributed by Ian Austen from Gander, Newfoundland, Vjosa Isai from Toronto, Judson Jones, a meteorologist, from Little Rock, Ark., Juliet Macur from Indianapolis, Katrina Miller from Carbondale, Ill., Sarah Maslin Nir from Buffalo, Dennis Overbye from Dallas, Emiliano Rodríguez Mega from Isla María Madre, Mexico, Simon Romero from Mazatlán, Mexico, Jay Root from Niagara, N.Y. and Jenna Russell from Houlton, Maine.