Tomorrow afternoon the streets of Edgartown will close, but the town will be far from quiet. The kickoff for this year’s Fourth of July festivities will have already begun, with an outdoor barbecue sponsored by the Preservation Trust on the lawn of the Daniel Fisher house. The familiar scent of grilled burgers and hot dogs will float through the town roads, enticing visitors and locals alike to fill their rumbling bellies as they wait for the first float to materialize on Main street. Finally, finally, the summer has arrived. And with it, some much needed sun. The weather has flip-flopped between rain and shine this week, but the National Weather Service predicts a sunny Independence Day, with high temperatures in the mid 70s.

The barbecue, an Island tradition that began over a decade ago, is the first of many celebratory options on a weekend that transforms the Island from a still-quiet vacation spot to the bustling tourist resort town it will remain until Labor Day.

Fella’s Catering provides the picnic fare for the barbecue, which is served concession style. There is no admission price, and the event is open to everyone. “People will bring their lawn chairs or bring a blanket and lie out on the grass . . . It’s really popular. [And] it’s very efficient, so there is not a lot of waiting [for food],” said Janet Heath, director of special events for the Preservation Trust.

Traffic will slow as people scramble to secure a place to park before the Edgartown Police close the parade route roads. According to the Police Department, traffic through the parade route will be stopped at 4:30 p.m. without exception. Trolley service will be offered to and from the town parking lot off Dark Woods Road, and visitors are encouraged to take advantage of the park and ride option to avoid the traffic headache.

This year’s parade, which begins at 5 p.m., brings three off-Island bands to Edgartown to provide musical entertainment. The Scottish Society will sponsor a visit from a Scottish fife and drum band, and the Colonial Navy Band and the Bay State Marching Band will join the music as well. The bands will also hold free performances at 2 and 7 p.m. at the Old Whaling Church. Flashy floats will dazzle excited children as they pull through the parade loop down Main street and wind through the narrow side streets of Edgartown.

The floats will pause before the selectmen, seated at the review stand in front of the Old Whaling Church. Cash prizes will be awarded to the floats voted most patriotic and most original. The overall grand prize amount is $1,000.

For a quieter and even more child-friendly way to celebrate, Islanders and visitors are invited to watch the Aquinnah children’s parade, organized by the Old South Road neighborhood association.

“It’s all of about five or ten minutes long,” laughed Aquinnah police chief Randhi Belain, who will lead the parade tomorrow beginning at 11 a.m. The parade consists mainly of local residents, and different activities, including face painting, will be available for children. The parade concludes with a children’s treasure hunt on Philbin beach.

Back in Edgartown, the energy of the celebration will begin to relax as the final marcher rounds the bend from Main street to the Edgartown school, but the fun will be far from over. From 6 to 8 p.m., the Martha’s Vineyard Shellfish Group and the Friends of the Edgartown Council on Aging will hold a raw bar fundraiser at The Anchors, across from the Chappaquiddick ferry.

“The exact idea is to make [the raw bar] after the parade and before the fireworks, when people are looking for something to do,” said Jay Sigler, who is involved with planning the event. “We’ll have at least 1,000 fresh clams and oysters,” he said. The event will resume this year after a long hiatus, but Mr. Sigler insisted that the shellfish group and the Friends intend to make it an annual event to complement the Fourth.

“We think it is a nice addition to the activities on the Fourth of July, and it doesn’t compete with anyone,” said Mr. Sigler.

As the darkness sets in, eager visitors will pray for cloudless skies to enjoy another unforgettable Fourth of July fireworks display.

With a $50,000 price tag, Atlas fireworks will unleash the legendary show over the throngs gathered in Edgartown at 9 p.m.

“We’ve been lucky in the sense that three years ago we started a campaign when we took over the fireworks,” said Melissa Vincent from the Board of Trade, the organization that sponsors the fireworks. Money collected from a fundraiser and from private donors has covered the cost of the fireworks show for the past two years, and will do the same this year.

“It’s important not only for the town of Edgartown but for the Island itself to keep the fireworks going. People count on it. People have been very good [about donating] even though it is a tough economy,” she said.

Though Saturday holds the main Fourth of July events, traffic begins to pick up a day or two before at the Martha’s Vineyard Airport and the Steamship Authority.

Because of the economic downturn, airport manager Sean Flynn said he expected a 20 to 30 per cent decline in air traffic for this year’s Fourth of July weekend. According to Mr. Flynn, Memorial Day weekend brought in average air traffic, but the weeks since have seen a noticeable decline compared with last year. Regardless, the amount of traffic through the airport always skyrockets for the Fourth.

“It’s a big weekend for us,” said Mr. Flynn. “It’s probably three times as much traffic [as last weekend].”

The swell in Fourth of July weekend traffic is no surprise to the Steamship Authority. Walk-on passengers should still have some luck getting a ferry ride to the Island today and tomorrow, but vehicle passengers are another story. According to General Manager Wayne Lamson, vehicle reservations sold out weeks ago. “We’re expecting a very busy weekend. They will be filling up all of our offsite parking lots,” he said of the tourists eager to escape to the Island.

The state of the economy — and the maddeningly drizzly weather — are likely to make this a quieter Fourth of July than the Island is used to. Hotels and inns are not expecting as many guests, and there are still rooms available to reserve in many. Stores and shops aren’t attracting the same business, and many have sale signs in their windows to try to entice customers. But the flags still wave in honor of Independence Day. The parade, and the fireworks will go on. The Vineyard is still ready to celebrate its ultimate summer holiday weekend, despite the setbacks.

“The whole day in Edgartown is like the quintessential American Fourth of July,” said Ms. Heath.