PHOTO: SHUTTERSTOCK

This year, April 8 will be the biggest day on the calendar for the city of Erie.

That’s when the next total solar eclipse — known as the Great North American Eclipse — will pass through the United States in a 125-mile-wide band, moving directly over Lake Erie near Presque Isle State Park. Day will turn to night there at 3:16 that afternoon — for 3 minutes and 41 seconds — the longest period of totality in Pennsylvania.

It’s such a rare event that Erie officials have been planning for what they’re calling, “The Ultimate Sunblock,” for almost two years.

The Flagship City expects between 65,000 to 250,000 people will visit to view the eclipse, says Christine Temple, director of communications for VisitErie. That estimate comes from GreatAmericanEclipse.com, which uses advanced mapping software, U.S. Census data and a road network model to determine how many people are likely to journey there.

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“We are the major city that’s closest to Pittsburgh, D.C., Baltimore and Philly,” she says. Erie is 6 hours from D.C. and 7 hours from Philly.

Most of Erie’s hotel rooms have been booked for months. (Fortunately, Downtown Pittsburgh is about a two-hour drive from Erie so folks can go up and back in one day if they like.)

In Pittsburgh, we’ll see a partial solar eclipse — though a more extensive occlusion than the eclipse in 2017, when thousands of Pittsburghers spilled out of office buildings, university classrooms, homes and shopping centers mid-afternoon to view the phenomena. That year the eclipse covered 81% of the sun here (totality was in Kentucky); this year it will be 97%.

“In math, 97 is close to 100,” says Amanda Iwaniec, director of theater experiences at Carnegie Science Center. “But with an eclipse — no. Totality is totality.”

Pittsburgh will be cast in shadow, not darkness like Erie, she says. But she didn’t want to downplay the Steel City’s experience. “We’re still going to see a pretty amazing thing.”

The next total solar eclipse in this area won’t arrive until 2144 — for our great-grandchildren — so if you want to see the total show, Erie is the place to be. And Cleveland, too, which also will experience totality (3 minutes earlier than Erie) as the celestial wonder moves diagonally across the United States from Texas to Maine.

Erie tourist officials are urging visitors to stay away from Presque Isle State Park; there’s only one road in and out and traffic is likely to be horrendous. Ideal viewing places will be Liberty Park, a large grassy area on Presque Isle Bay in the city’s Bayfront District, as well as Shades Beach, east of the city, and Freeport Beach.

Still, because the sun will be high in the sky and above the treeline at 3:16 p.m., people will be able to see the eclipse from just about anywhere in Erie.

What Erie can’t control is the weather. Historical data shows that April 8 has a 60% chance of cloud cover, Temple says. “Let’s be real. We’re Erie, we’re not the Sunshine State.”

The sky still will turn to a deep twilight during the eclipse whether it’s cloudy or sunny, she says.

A planning committee has put together a website that lists everything viewers need to know.

Also, the American Astronomical Society has compiled a list of certified suppliers of safe solar filters or glasses. People can damage their eyes if they look directly at the sun during an eclipse. The society strongly recommends not going to Amazon or similar sites because there is no way to validate those glasses are safe.

If people do plan to journey to Erie, Iwaniec of the Carnegie Science Center says the most important thing is to map out when and where to go.

“It’s important to make a plan,” she says. “This is a once-in-a-lifetime opportunity.”