On Monday, at 3:22 p.m. ET, darkness will descend upon the small city of Watertown, New York. For a few minutes, at least. 

That’s because Watertown—along with cities such as Cleveland, Indianapolis, Dallas, and others—lies in the path of totality for the rare total solar eclipse that will occur on April 8. For Watertown, a city of roughly 25,000 people located 300 miles northwest of New York City, it’s shaping up to be a once-in-a-lifetime economic boon, as visitors from all over the world will descend upon the town to see the eclipse.

“We have people coming from as far away as Italy, South America—all throughout the country,” says Sarah Compo Pierce, the mayor of Watertown. “It’s really crazy when you think about it. Every hotel room in the city has been sold out for a year.”

She adds, “Any time you have tens of thousands of people spending money in stores, restaurants, gas stations—that’s going to be an economic boost for the city.”

Just how big of a boost? It’s hard to say, exactly. Pierce says it comes down to a few key variables: How many people show up, how much they will spend, and most importantly if the weather will hold up. Luckily, the forecast is calling for sun and a high temperature near 60 degrees on Monday.

The last eclipse in the United States occurred in 2017 and drove hundreds of millions of dollars in spending. In Wyoming, for example, the 2017 eclipse drew 192,000 visitors to the state, and boosted its economy by more than $63 million. Similarly, more than 600,000 people trekked to Nebraska, blasting an estimated $127 million into its economy.

It’s expected that this year’s eclipse will prove even more fruitful for the states, cities, and towns fortunate enough to be sitting on the line of totality, or around it.

As such, for Watertown, and many other cities and towns across the country, the eclipse may prove to be an economic windfall unlike any they’ve ever experienced, and likely won’t for some time. In fact, cities in the contiguous United States won’t see another total solar eclipse until August 2044.

Small duration, huge impact

While Watertown is holding a viewing party in a public park that’s expected to draw perhaps 10,000 people, other cities in other states are anticipating even larger crowds—and even more money injected directly into local communities.

“The duration is compact, but the impact is huge,” says Bulent Temel, an assistant professor of practice in economics at the University of Texas at San Antonio. “Texas will be the biggest beneficiary this time around,” Temel explains, in large part because three of the state’s four largest metro areas are in prime position for the eclipse: Dallas, Austin, and San Antonio. 

On a wider scale, Temel estimates that across the 15 states that are on the line of totality, the revenue generated by the eclipse could top out at $1.5 billion. “There are sports events, like the Super Bowl, concerts, Taylor Swift—in Austin, we have South By Southwest once per year, which brings hundreds of thousands of people and revenue,” he says. “But none of those are as economically significant as this one.”

Invisible sun, invisible benefits

Not only is the eclipse expected to pay immediate economic dividends, but experts also say that it will pay out future ones, too. Temel says that “the most significant impact of this event is the invisible impact it’ll have,” meaning that it should lead to future tourism as people visiting for the eclipse may want to return in the future.

“People visiting the state of Texas are potential future tourists who will want to come back to the state,” he says. As such, the eclipse could lead to “invisible and indirect income generation down the line.”

That’s a point likewise hammered home by Michael Pieciak, the state treasurer of Vermont, a portion of which is also on the line of totality. “It’s a real opportunity for the long-term to continue to attract tourism,” Pieciak says.

Pieciak’s office released an analysis of the potential economic impact on the state from the eclipse, and his estimates show that Vermont could see a spending tally up to around $52 million.

“When we were looking at our estimates, there were two variables that matter: How many people are coming to your state, and how much they will spend,” he says. “We looked at Wyoming, Nebraska, and South Carolina’s [data] following the 2017 eclipse, and tried to get an average of what people spent in those states.”

Adjusting for inflation, his office was able to put its report together—but Pieciak now thinks that the true numbers will blow past the estimates.

“We could see a total number of folks we haven’t seen in Vermont in quite a while,” he says. Assuming the weather holds out—which it should.

Given that Vermont won’t see another eclipse until 2106, people in and around New England may want to make the trip to see it now, he says. He estimates that more than 200,000 people will travel to Vermont to see the eclipse, which may lead to some grumbling from the locals. But when all is said and done, the state, overall, should benefit.

“Vermonters can get kind of cranky when their daily lives are disrupted,” he says. “But there’s an economic benefit that’ll come with it.”

This story was updated to reflect more recent estimates from economic experts.