Boynton Beach's week builds to one big Saturday. The city throws its free Fall Festival downtown on October 17, a free Latin band plays under the stars out west that same night, and the days around it are full of the small, good things a family can actually fit into a school week. Here is what is worth your time from October 13 to 18, each item checked with the people running it.

Thursday: a free Halloween book at the library

The Boynton Beach City Library's Picture Book Club does Creepy Crayon!, by Aaron Reynolds, on Thursday, October 15, from 4:30 to 5:30 p.m. at 100 E. Ocean Ave. Kids ages 5 to 11 hear the story and make creepy snacks, and every registered family takes home its own copy of the book, one per household while supplies last. Registration is required. Sign up through the city.

Why go: an hour after school, a snack project and a free book on the shelf for Halloween.

Friday: Trunk or Treat at the Y

The DeVos-Blum Family YMCA of Boynton Beach, 9600 S. Military Trail, turns its grounds into a Halloween night on Friday, October 16, from 6:30 to 8:30 p.m., with trunk-or-treating, a magician, stilt walkers, a corn maze and food trucks. The price is one bag of candy per person if you register ahead of time; on the day, it is $15 per child and $5 per adult. Families can also decorate a trunk for a shot at gift cards by registering at the front desk, with setup from 5 p.m. Note that the branch closes early that day. Details from the Y, or call 561-738-9622.

Why go: register now and a bag of candy gets the whole family in, which is the best Halloween deal in town.

Saturday morning: Green Cay's free programs

Green Cay Nature Center, the county's wetland preserve at 12800 Hagen Ranch Road, runs free programs on Saturday, October 17, with no reservations needed and every age welcome: animal feedings at 10 a.m. and 2:15 p.m., and an ethnobotany tour, about how people have used the plants around you, at 11 a.m. The nature center is open Wednesday through Saturday from 9 a.m. to 3 p.m., and the boardwalk is open every day from sunrise to sunset. No pets, food or bikes on the boardwalk. Program list from Palm Beach County Parks.

One heads-up: the center is closed on Tuesday, October 13, for a county holiday, according to the county's Green Cay page.

Why go: a free morning on one of the best boardwalks in the county, with a guide.

Saturday at 1: kids read to therapy dogs

Bones to Books at the City Library pairs young readers with certified therapy dogs from Bonafide Therapy Dogs on Saturday, October 17, from 1 to 2 p.m. It is aimed at early readers through elementary school, though all ages are welcome, and registration is required. Register through the city, or call 561-742-6390.

Why go: a patient dog is the least judgmental audience a shy reader will ever have, and the library is steps from the Fall Festival, which starts two hours later.

Saturday afternoon: the city's Fall Festival

The main event. The City of Boynton Beach's Fall Festival runs from 3 to 6 p.m. on Saturday, October 17, at Centennial Park and Amphitheater, 120 E. Ocean Ave., next to City Hall. It is free, with games for families and kids of every age. Free parking is at the corner of Boynton Beach Boulevard and Seacrest Boulevard, entering from Boynton Beach Boulevard, and the city encourages ride share. E. Ocean Avenue and SE 1st Avenue close to cars from about noon to 7 p.m., so plan your route. Event details from the city.

Why go: it is downtown Boynton's own fall party, it costs nothing, and the library program above makes it an easy double.

Saturday night: Mojito Latin Band, free, under the stars

Out west, Palm Beach County Parks' Legends on the Lawn series brings the Mojito Latin Band to the Canyon Amphitheater, 8802 Boynton Beach Blvd., with music starting at 7 p.m. on October 17. It is free, and lawn chairs and blankets are welcome. If weather moves in, staff will clear the grounds and let people back in once it passes. Series details from the county.

Why go: after an afternoon of kids' games downtown, a free Latin band on a lawn is how the grown-ups get their Saturday night.

The short version

If you only do one thing, make it Saturday: Green Cay in the morning, therapy dogs at 1, the Fall Festival at 3 and the Mojito Latin Band at 7. That is a whole day in Boynton Beach, and almost all of it is free.