WORCESTER — The first day of the Cars of Summer Car Show at Green Hill Park was a washout, leaving organizers optimistic for sunshine and a good turnout for the rest of the holiday weekend.

“The first day is typically a shakeout day,” said organizer Roger Steele, a Worcester police captain. “Our sense is that it’s going to be busy” on Saturday.

About a dozen people relaxed under the park shelter as a live band performed above the patter of rain just before 1 p.m. Friday. The show was essentially over for the day and most had packed up and left.

“We’ll stay at least until the band stops,” said Allen Baer, of Worcester.

Showing off his ’64 Chevy C-10 green with gold oak bed, Mr. Baer said he has been coming here for about 20 years.

“There’s nothing you can do about the weather,” he said.

Allen Obshatkin, of Northboro, agreed.

“It’s better than cleaning out the garage,” he said.

Nearby, Mike Lento, of Weymouth, sat with other members of the GFY auto club — described as “a club that’s not a club,” where there are no dues, no hierarchy, “just people with the same interests.”

He said that he and his family brought their ’77 Corvette to show for the first day and were not deterred by the rain.

“It’s only water,” he said. “We come here and relax — it’s our getaway.”

The biggest difference the weather made was leaving the ’72 Gran Torino at home, because he said it has so much horsepower he likely wouldn’t be able to drive it in the rain.

Mr. Lento explained that the club brought only three of the 10 cars it will likely show because higher-quality show cars require much more work if exposed to a rainstorm.

“You have to clean every inch of it,” he said, since it will accumulate grime from the road and could result in water stains.

Motioning to the Corvette, a ’79 Mustang, and a ’60 Thunderbird, “these you wipe off and detail and it isn’t so bad.”

While many of the others had packed up and gone, food vender Bill Belanger estimated that he had roughly 10 customers by about 1 p.m.

“We fight the weather all summer,” he said. “Even if we break even on a day like this I’m happy.”

The show went on through brutal heat last year, so organizers have set up misting stations and hired shuttles to drive visitors for free from the parking area up the hill as well as around to the different areas of the park. There is also a free children’s tent and live bands.

Mr. Steele said that in addition to auctioning antique cars, visitors can bid for about 100 other novelty items.

This is the second year for the Cars of Summer show, which attempted to fill the void left by the 22-year reign of the New England Summer Nationals at Green Hill Park. Last year, Summer Nationals, run by Robert Moscoffian, was relocated about 25 miles south to Thompson International Speedway because of conflicts with the city.

While Mr. Moscoffian has vowed to return in 2015, he did not put on the show this year, citing health issues.

“He did a real good job for many years,” Mr. Steele said, adding that the goal of the Cars of Summer was to continue the tradition of a car show at the park, which he said car enthusiasts across the area look forward to every Independence Day weekend.

The Cars of Summer show will be open Saturday from 7 a.m. to 7 p.m., and Sunday from 7 a.m. to 3 p.m.

Admission is $10 for one day, or $35 for a weekend pass. Children under 12 are admitted for free.

Contact Alli Knothe at allison.knothe@telegram.com. Follow her on Twitter @KnotheA