All Weekend

The Butterfly House - Smithtown. Learn the various stages of the butterfly's life cycle, view butterflies, and color a butterfly to take home. Cost: $5, $3 seniors and kids under age 11.

Long Island Family Festival - Copiague. 11am-10pm. Games, rides, food, live music, pet expo, crafts, fashion show, balloon twisters, skate jam, cruise show and more. Cost: Free admission.

Merrick Chamber of Commerce Fall Festival - Merrick. 11am-11pm. Carnival rides, games, food, craft fair, jewelry boutique. Cost: Free admission.

Our Lady of Lourdes Italian Feast - West Islip. Rides, games, Italian food. Cost: Free admission.

Fall Festival & Craft Show - Riverhead. 12-5pm. Hallockville Farm will host more than 50 artisan craft and folk art vendors: jewelry, baskets, clothing, artwork, soaps, candles, something for all ages and interests, folk art demonstrations and more. Also, hayrides, tractor pull and antique farm machinery display from LIAPA, model trains from the Railroad Museum of LI, children's activity area, and a dance performance from the Blue Spruce Cloggers Additional amenities that are available for purchase include children's mini train ride and pony rides. Cost: $8/adults, $5/children (or a family of 4 with 2 adults, 2 kids = $20).

Farmingdale Village Downtown Music Festival - Farmingdale. The festival is free to attend and will be held from 1pm- 9:30pm on Saturday 9/13, and 1pm - 7:30pm on Sunday 9/14. Kids Zone, Kids Stage including I Love Reading & Magic, Very Cool Music School and School of Rock performances. Cost: Free admission.

Saturday, September 13

Kerry Wirth in Concert - Huntington. Kerry Wirth will play at The Sandbox Playspace. Cost: $15/child.

Arts in the Plaza - Long Beach. Exclusively handcrafted art and crafts by Long Island artisans. Live music. Free Kids Art Station. Kennedy Plaza Farmers Market. Cost: Free admission.

Incredible Ink Meet the Author Event - Garden City. Author Brianne Farley of Ike’s Incredible Ink for a book reading and meet and greet. Cost: Free.

Grown Up & Me Yoga - Bellmore. Parent/caregiver and child yoga at Emerge. $15/class.

Parents Night Out - Smithtown. Drop off the kids at Lil' Builders for snack, dinner, beverages, play, Legos and more. Cost: $35/first kid, $25/siblings.

Outdoor Movie: Frozen - Long Beach. Watch Frozen on the beach. Bring your own blanket and chair. Free popcorn will be served. Cost: Free.

Free Craft for Kids at Lakeshore Learning Store - New Hyde Park. Anytime between 11am and 3pm, kids visiting the store can create a different, fun craft on Saturdays. Cost: Free.

Train a Seal, Kiss a Sea Lion at the Long Island Aquarium - Riverhead. Bring the kids to the Long Island Aquarium in Riverhead on Saturday for a fun-filled day of behind-the-scenes action. During the event, which runs from 10:15am to 2:15pm, kids will be able to get up close and personal with some of the creatures that call the aquarium home. Cost: $155 per person.

Science Saturday at the Long Island Science Center - Riverhead. Kids can learn and play at the Long Island Science Center with over 30 hands-on exhibits. The center is open from 11am to 4pm. Cost: $5 per person.

Sunday, September 14

Apple Festival -Stony Brook. Farmer's Market, all things apple, games and kiddie fun. 11am-5pm. Cost: Free admission.

Heckscher Family Hour - Huntington. Children ages four through eight and their families are invited to join museum educator Tami Wood for a family-friendly tour of the Museum's current exhibit. Cost: Child admission free, $5/activities.

Sunday Seatuck Family Nature Club - Islip. Birds, trees and seasonal things. Cost: Free

LEGO Club at CMEE - Bridgehampton. Children's Museum of the East End, Bridgehampton, 10am. Children can construct works of art using the thousands of Legos at the Museum. Cost: Free with admission. NOTE: CMEE will be closed after 5pm on Sunday, August 31 and all day Monday, Sept. 1 - Friday, Sept. 5 for their annual fall clean up.

Mommy/Daddy Me Anti-Gravity Yoga - Bellmore. Have your little one explore the Anti-Gravity hammocks while building basic motor skills. All kids AGY classes are structured to introduce basic life skills and build confidence in a light-hearted way while having fun. Cost: $20.

Family Sundays at the Nassau County Museum of Art - Roslyn. Each Sunday, Nassau County Museum of Art offers a 1pm docent-led family walk-through of the exhibition and supervised art activities for the whole family beginning at 1:30pm. Special family-friendly gallery guides of the main exhibition are in the galleries.