Phil Powers (left) and Mike McLaughlin, working a traffic detail at the middle school, take in the fireworks show at last year’s Family Day. FILE PHOTO/JERRY SPAR

Organizer Pat O’Brien is optimistic about this Saturday’s Hopkinton Family Day.

“The weather’s going to be nice,” said O’Brien. “That’s the main thing we’re looking for.”

The Friends of Hopkinton, which organizes and runs Family Day annually, has been putting final touches on the event in the last few days and hours, according to O’Brien. He noted that about 40 local organizations are set to participate. Interactive events will include sports from local youth programs, inflatable bounce houses for younger kids and a dunk tank.

O’Brien emphasized that there will be two stages this year for live music, “so there’ll be no downtime in entertainment.” He also teased an appearance by Hopkinton Police officer Nicholas Walker and his K-9 unit, Kobe.

“[Walker] is going to be putting on a display with his K-9,” O’Brien said.

One of the organizations participating in Family Day is Troop 4 Hopkinton. Before the event begins, the Scouts will construct a 35-foot-long monkey bridge using double A-frames, walking ropes and side handrails. According to Troop 4 Scoutmaster Joe Gill, kids will be able to walk across the bridge once it’s constructed.

Troop members also will be teaching knots and lashings using rope and wooden staves. “Kids will be able to put their new skills to the test by building a pioneering gadget like a camp chair or tripod,” Gill stated in an email.

This year’s Family Day will kick off at 3 p.m. — another change from past years. O’Brien confirmed that fireworks will start around 8 p.m. He warned residents to be mindful of parking, adding that there will be handicapped spaces available behind Hopkinton Middle School, toward the athletic fields.

O’Brien also noted that residents will not be able to access the event by walking down Center Trail and exiting onto Loop Road. He explained the decision to close off the road and the trail was to keep residents out of the perimeter of the fireworks.