The city is looking forward to welcoming this year’s 36,000 Boston Marathon partipants and moving beyond the shadow of last year's deadly bombings. (Reuters)

Most years — which is to say, all of them but the last — the three-day weekend culminating with Patriots’ Day, always the third Monday of April, is when you will find Boston at its cheeriest, its prettiest, its best. It is the weekend New England comes out of its thick winter shell. It is the start of the Boston public school system’s week-long spring recess. And not least of all for this sports-crazed populace, it is one sprawling buffet of big-ticket sporting events upon which the whole city gorges.

By this point in the calendar, the Bruins and Celtics are typically launching their playoff runs — though this year the Bruins are going it alone, the rebuilding Celtics having missed the NBA playoffs. The Red Sox are always home for the weekend, with a traditional, bleary-eyed 11:05 a.m. start on Patriots’ Day itself. (Bravely performing its civic duty, the Cask ’n Flagon bar across the street from Fenway Park will open at 7:30 a.m. for the occasion.)

And then, of course, there is the marathon.

The Boston Marathon is both an elite race and an open competition for any amateur who can qualify, which is a large part of its appeal. You can’t play Augusta National while the Masters is going on or drive Indianapolis Motor Speedway during the Indy 500, but you can run Boston at the same time as the world’s best marathoners.

It is both a civic treasure and an international icon. It is, in a way, Boston’s Patriots’ Day Parade, with children and whole families and beer-swilling college kids lining the streets to cheer — not for floats and marching bands and clowns but for tens of thousands of sweaty, steady runners.

“I think Patriots’ Day is one of the most beautiful days around here,” Red Sox slugger David Ortiz said this week. “And I think we should keep it the same way — especially now.”

Especially now. The 118th edition of the Boston Marathon, which starts Monday at 8:50 a.m., will be unlike any of others that went before, owing to the events of a year ago, when a pair of bombs exploded near the finish line, killing three, injuring hundreds and ultimately deepening the bond between this city and its signature sporting event.

“I think [Monday] is going to be very emotional,” Ortiz said. “But it’s going to be happiness more than sadness because of the way this city bounced back.”

Around this time of year, Bostonians find themselves explaining to non-Bostonians what Patriots’ Day is all about. Though it is mostly celebrated now as an excuse to drink beer and/or play baseball before noon, Patriots’ Day actually commemorates the first battles of the Revolutionary War and Paul Revere’s famous ride.

“Patriots’ Day symbolizes everything we know as ‘Boston Strong,’ ” said Tom Grilk, executive director of the Boston Athletic Association, which organizes the marathon, “because the conviction that people here will live their lives as they choose, no matter what anyone does to try to stop them, goes back to colonial Boston.”

Scott Kerman, a resident of Brookline, Mass., and a longtime Red Sox season ticket holder, has a more succinct way of explaining it: “I always tell people, ‘Look, we started this country — and we have this day,’ ” he said Sunday while joining the thousands strolling around the marathon’s finish-line area on the eve of the race.

On Monday, Kerman and his sons will be part of the hordes upholding a long and beautiful Patriots’ Day tradition — rooting on the Red Sox at Fenway Park, then hustling over to Kenmore Square to watch the marathoners, now approaching the 25-mile mark, make the turn onto Commonwealth Avenue.

“It truly is our day,” Kerman said. “It’s the best day of the year.”

The forecast for Monday calls for 64 degrees and sunshine — perfect baseball weather, perfect marathon weather, perfect Boston weather.