Summer Bucket List - Kew Gardens,NY

Children's museum - get passes from the library. There are usually exhibits that appeal to different ages, so get the kids to share some time in one, then the other.

Aquarium, same deal.

Simple stuff like nature walks or beach combing - take a bucket and pick up interesting stones, bring them home and wash, let dry, and paint. Give Grandma and Uncle Joe a paperweight, or put them on the balcony in flower pots or in a garden as decorations. In the late summer, find pine cones and tie a loop on them, put peanut butter on them, then roll in bird seed: poof! Instant bird feeder. Collect leaves in different shapes and make collages or spray paint on them as if they are stencils. Get a craft book or camping fun book at the library - great ideas from books from the 50s and 60s before everyone did everything on a computer or an iPhone.

Don't feed the ducks bread though - it's really bad for the ducks, it interferes with their ability to find healthy food, and their excrement fouls the water. (I know, I know, I enjoyed it as a kid, but it's pretty much forbidden in all responsibly managed ponds.)

Firehouse is great - our firefighters let the kids climb in the truck, learn about the helmets and masks, and look in the ambulance.

Farmers markets or farm stands - seeing real food growing also increasing kids' willingness to eat new foods.

Scavenger hunts with another family's kids - hide fun things in the park or the yard. Get those plastic Easter eggs and put stuff in them (chocolate kiss, hot wheel car...) and tuck them in shrubbery or notches of trees.

Thrift shop or flea market - find dress up items, things to create costumes, or props for imaginative play.

Oh I don't know.
My husband and son (now 18) STILL like touring a firehouse when ever they get a chance.
Don't over look the cardboard box fort - you can make so many different things - it never gets old.

Make forts in your living room. (Great for all ages).
Zoo
Library (reading time or some have areas with toys)
Indoor mall or shopping area?
Google small toy shops in your area (some have an area for the kids to play
with the toys)
Park (take plenty of snacks and drinks)
A walk in the neighborhood (be safe)
Buy a small blow up pool or those hard blue ones to put in your backyard, front
yard or side yard (whatever you may have...even if space is limited you can
often find a place)
Buy big, soft building blocks & have a building party on your living room floor
Have an indoor picnic on your living room floor complete w/blanket & snacks
visit a pet store just to browse & see cute animals
Indoor scavenger hunt for your oldest
Pirate booty treasure map with treasure chest filled with things at the end (it
can be a shoebox filled w/small goodies/candy from around the house)
Make cupcakes
Have popsicles indoors
Make an indoor fair (fish game using a twig, string & clothesline pin)
Make an indoor zoo or circus w/stuffed animals
Look for moms' groups

swimming, boat ride, nature scavenger hunt at a park. bake cookies together ( cutouts so they can do the shapes) play in the rain, catch a fish (or just go fishing in general)

At this age, my kids LOVED the simple things like going for a walk near a lake and feeding ducks some bread or watching the fish. Or going to a local pick-your-own strawberry farm (mostly eating them at this age while you pick them); same for an apple orchard in the fall. Hopefully you can do some of that kind of stuff within a short drive of NYC?

Our library has a TON of free activities in the summer. They are mostly ones that would appeal to your age group (more so the older one), but wouldn't in a year or two.

Good luck!

Water balloon fights, build simple wooden boats and then race them, play in a shallow creek, skip rocks, make slime, play miniature golf, make fresh-squeezed lemonade, stargaze, play Frisbee, make popsicles, have a nature scavenger hunt, plant something, make s'mores, ask for a tour of the library (so you can see what happens behind the circulation area).

Look for ways for them to volunteer. A group of our kids from our neighborhood painted small rocks and added messages like "Have a good day", "Pass it on", and "Smile" and hid them along walking paths in area parks, just to make someone else's day a bit brighter.