In the early days of the Island’s busiest season, there are many events billed as unofficial “welcome to summer” celebrations. Memorial Day weekend is generally considered the kickoff to the summer season, after which many stores extend their hours, many beaches require passes, and motorists begin to heed time limitations for parking spots, lest they find themselves graced with a ticket from a seasonal, special police officer.

But according to the calendar, summer officially begins on June 21, and we’ve got a celebration to mark that date, too.

This year, the Oak Bluffs Harbor Festival and Summer Solstice Festival comes a couple of days early, on Saturday, June 19. Vendors will begin to set up shop on the strip along the harbor, between Nancy’s Restaurant and Our Market, early, at around 9 a.m. And though the event isn’t scheduled to begin until noon, Terry McCarthy, board member for the event sponsor, the Oak Bluffs Association, said people will start to trickle in as soon as the vendors arrive.

“It’s a festival meant to celebrate spring and kick off the summer,” said Mr. McCarthy this week.

The Harbor Festival comes first, from noon to 5 p.m. And then, as the air begins to cool and the evening sets in, the activity moves to Circuit avenue, where an antique car parade at 5 p.m. kicks off part two of the event: the Summer Solstice Festival.

The Harbor Festival began 19 years ago as a sort of celebration of the Oak Bluffs harbor, said Mr. McCarthy. And though the event has strayed from that a bit in recent years, he said that they’re trying to get back to their roots. “We’re trying to get back to that.”

Despite the rain that often plagues the Vineyard through May and into the month of June, Mr. McCarthy said that Harbor Festival weekend has always been lucky. “We’ve been really blessed over the years with good weather,” he said.

All the better to take a leisurely stroll along the sidewalk speckled with racks of summer tees and tanks and grab a bite of strawberry shortcake or a seafood treat to the backdrop of live music from Chad Burch and Friends and Johnny Hoy and the Bluefish, wafting from the deck at Nancy’s.

“It’s the whole gamut of things you can have here,” said Mr. McCarthy of the Harbor Festival food, shopping, and entertainment options.

For the kids, visitors can sit back under the shade of the willow trees in Sunset Lake park from noon to 2 p.m. to watch the Blessing of the Animals by Father Nagle of the Good Shepherd Parish. The animal fun continues with dog shows and pony rides in the park.

“This is going to be a pretty full day of events,” said Mr. McCarthy.

This year’s festival expects around 40 vendors, and Mr. McCarthy said there will be some new ones to get excited about, namely Johnny Cupcakes. Though the name might suggest a booth full of confectionery treats, the Johnny Cupcakes table will actually hold a selection of cheeky T-shirts.

Marketing director Michael Finkle said that owner Johnny Earle has been in the clothing business since age 19, selling limited edition tees on which popular images and logos are replaced with designs that mimic the originals. “The company basically started as a joke, and [Johnny] was poking fun at pop culture,” said Mr. Finkle. Now, he’s got a store in Boston, one in L.A., and the title of New England’s young entrepreneur of the year, for 2008, from Business Week magazine.

The young clothing designer was drawn to the Harbor Festival after years of spending summer vacations on the Island. And now, festival visitors can step up to his booth to enter a raffle for one of his quirky tees.

“They’re kind of collectible,” said Mr. Finkle, describing the goods. The staple image, he said, is a play on the skull and crossbones, with a cupcake in place of the skull. “We only do the shirts once, and once they’re gone, they’re gone forever,” said Mr. Finkle.

Mr. McCarthy said that the Oak Bluffs Association is excited to have Johnny Cupcakes at the festival this year. “You have new vendors, but you never know which one is going to click,” he said. But Johnny has proved his popularity across the country, and Mr. McCarthy thinks kids, especially, will be excited to see him on the Island. “He’s pretty well known.”

When the booths along the harbor begin to shut down in the late afternoon, so too will traffic down Circuit avenue. As the orange cones spring up at the bottom of Oak Bluffs’ main street, people can wander out of storefronts and into the road to kick off the 5th annual Summer Solstice celebration.

“We’re encouraging people to come and stroll the street without any cars being in the way,” said Oak Bluffs Association president Dennis daRosa. Of course, they’ll have to make way for the string of vintage cars as they cruise down the street. But once the parade closes, the drivers will put them into park and leave them on the road for passersby to admire.

The road will stay closed until 11 p.m., but it won’t be empty. “Most of the restaurants are going to be serving out on the street, al fresco,” said Mr. daRosa. “That’s a really beloved event when the weather is great. And it looks like the weather is going to be great on Saturday.”

While some will be content to sit with a plate full of food and a crisp glass of wine in front of their favorite restaurant, others will be eager to check out the various activities being held up and down Circuit avenue. Phil daRosa and friends will play live music outside of Seasons, and dancer Karen will lead the crowd in hula hoop dancing.

A new addition to the lineup this year is fire dancer Martina. “She popped out of the blue last week,” said Mr. daRosa. “She’s going to do a fire dance. She uses flaming torches. It’s like a circus act, I guess.”

Mr. daRosa said Martina mainly performs at parties, but her festival fire-dance will keep with theme of the blazing sun on the longest day of the year.

Mr. daRosa said that the Summer Solstice festival is all about ambience, and people look forward to seeing Circuit avenue turn inside out to bid farewell to spring, and prepare for the swell of summer activity. “In years past, it’s been a nice little evening out for people before the crush happens,” he said.