Yes, the South Boston St. Patrick’s Day Parade is happening this year. Here’s everything you need to know.

After a two-year hiatus, the South Boston St. Patrick’s Day Parade is back this weekend with a shorter route. Here’s everything you need to know to celebrate this Sunday.

What’s the South Boston St. Patrick’s Day Parade route this year?

The parade will run a shorter route this year, starting at the Broadway T Station, running down West Broadway to East Broadway, and ending at Farragut Road. In previous years, the route looped around at City Point and continued to Dorchester Heights and Andrew Square.

When does the parade start?

The parade will step off from Broadway Station at 1 p.m. Sunday, March 20.

How can I get to the parade? Where can I park?

The MBTA Red Line stops right at the parade’s starting point, Broadway Station. The T typically runs at rush hour schedule on parade day to accommodate the crowds.

A note to bus passengers: Routes 9, 10, 11, 16, and 47 will be detoured around the parade route Sunday, and buses will not stop at Broadway or Andrew Stations starting at 9:45 a.m. until crowds clear.

Suburban parade-goers can take the Commuter Rail to South Station and hop on a free shuttle from Summer Street to East 1st Street in South Boston, which will run between 10:30 a.m. and 6 p.m.

Parking is notoriously difficult on parade day, with road closures and crowds.

“Driving to the South Boston St. Patrick’s Day/Evacuation Day Parade is not recommended,” parade organizers note on their website. “Parking will be limited due to the influx of people coming to South Boston for the event, in addition to street closures.”

Do I need to wear a mask?

Boston no longer requires people to wear masks indoors, or at large-scale events like the parade. If you take public transportation to the parade, however, be aware that the federal requirement to stay masked on buses and trains is still in effect.

Can I watch the South Boston St. Patrick’s Day Parade from home?

Yes, you can. It will be broadcast live on NECN.

Why is the parade route shorter this year?

The decision to shorten the route was made during the height of the Omicron variant wave, when it was not clear whether large-scale public events would be safe by St. Patrick’s Day weekend.

“We understand how meaningful the traditional route is to South Boston, with the parade incorporating Dorchester Heights where Evacuation Day was made possible,” Dave Falvey, commander of the South Boston Allied War Veteran Council, said in a statement. The focus this year, he said, was to “bring the parade back in some form for 2022, even if not the full route, after two very long years away.”

Bryan Bishop, director of parade operations for the South Boston Allied War Veteran Council, told public safety officials in a Zoom meeting Wednesday that the shorter route is due to both COVID concerns and public safety concerns. He cited an attack on a Christmas parade in Wisconsin last year in which a driver sped into the crowd, killing six people and injuring 48.

“This is the first time in two years that this parade has taken place, and at the same time it’s the first time in two years that Boston is going to see a crowd descend on South Boston like it’s going to see, because ... people have been pent up for two years,” Bishop said Wednesday.

State Senator Nick Collins, whose district covers all of South Boston, asked why the parade route can’t be protected with Jersey barriers.

“This thing’s been done for 100 years and, unfortunately, terrorism has been around a lot longer, and we’ve been able to keep the place safe,” Collins said during the meeting Wednesday. ”I have every trust that the committee and the police department can do that with the official route because it’s been done before.”

What is St. Patrick’s Day anyway, and why do people celebrate it?

Ireland’s primary patron saint was a man born in Britain in the fourth century, according to Philip Freeman’s book “St. Patrick of Ireland: A Biography.” Stories about him driving the snakes out of Ireland are likely false, since Ireland never had snakes, Freeman told the Globe in 2016. And the tale about him using shamrocks to illustrate the holy trinity, of the Father, the Son, and the Holy Spirit? Also a myth, Freeman said.

Though little is known about his life, historians believe he was born to a rich British family, kidnapped as a teenager, and sold to an Irish farmer, according to Freeman. He spent six years as a slave before he escaped back to Britain, but returned to the country as a Christian missionary.

Today St. Patrick’s Day is used to celebrate Irish cultural heritage, though people without Irish ancestry often celebrate as well.

Want to cook up a celebratory meal at home? Here are recipes for traditional corned beef and cabbage; Irish stew and shepherd’s pie; the Dubliner Irish Pub’s soda bread; and for a sweet treat, the Dubliner Pub’s Irish shortbread. You can also follow chef Gordon Hamersley’s lead and braise oxtail in some Guinness.

I’m new here. What’s this Evacuation Day I keep hearing about?

In Boston, St. Patrick’s Day Parade also commemorates Evacuation Day, the day in 1776 that British forces withdrew from Boston. It happens to fall on March 17, the same day as St. Patrick’s Day, and it’s officially observed in Suffolk County.

In early March of 1776, British troops were closing in on Boston. George Washington, then commander in chief of the Continental Army, ordered the construction of fortifications at Dorchester Heights, and a 25-year-old named Colonel Henry Knox brought in cannons from Fort Ticonderoga in New York. Two weeks later, the British forces withdrew from the area.

The evacuation is celebrated in South Boston every year at a ceremony on Telegraph Hill.

You can watch this year’s ceremony here:

What is the history of St. Patrick’s Day in Boston?

Celebrations of St. Patrick’s Day in Boston precede the founding of the United States. The first recorded celebration was March 17, 1737, the day the Irish Charitable Society was founded in the city. Early celebrations included banquets and and parades downtown, near the Ancient Order of Hibernians.

In 1901, the parade moved to South Boston, where many of Boston’s Irish residents had settled, according to parade organizers. Because of the neighborhood’s proximity to Dorchester Heights, it came to celebrate both the patron saint of Ireland and Evacuation day.

But the oldest recorded celebration of St. Patrick’s Day in what is now the United States came more than a century before that, far outside of Boston. Michael Francis, a history professor at the University of South Florida in Tampa, found recordings of residents of St. Augustine, Fla., honoring the patron saint of Ireland as early as 1600, likely at the behest of one of two Irish residents, one of them a priest named Richard Arthur. There was a record of residents firing a cannon to celebrate Saint Patrick in August of that year, he told the St. Augustine Record newspaper in 2018, and another record of a parade or procession in the saint’s honor on March 17, 1601.

“It is likely that Richard Arthur was responsible for the Irish saint’s short-lived prominence in St. Augustine,” Francis wrote in an article for PBS in 2017. “When Arthur disappears from the historical records, so too do the references to the Irish saint, and soon thereafter, the memory of the St. Patrick’s Day celebrations and processions began to fade from public memory.”

Please help: Is it St. Paddy’s Day or St. Patty’s Day?

For the love of all that is holy — St. Paddy’s Day.

Globe correspondent Nick Stoico contributed reporting.

Gal Tziperman Lotan is a former Globe staff member.