Beat the heat with stylish swimsuits at the pool, sur la plage, or on any city playground.

Little swimmers can frolic in I-Play’s Ultimate Swim Diaper. Available in animal prints and Hawaiian surfing patterns, the moisture-wicking diapers are made of a woven nylon fabric containing 50+ UPF, meaning no more landfill-clogging disposables for you.

Floaty swimsuits by Archimede are made with foam flotation pieces that eliminate the need for a separate life jacket. So you can (semi) relax around the pool. Bonus: Remove the floaties as your child’s swimming ability soars.

For the over 4 set, it doesn’t get more adorable than Marimekko one-pieces in the iconic Unikko flower print and tankinis in a Punapippuri pattern (Marimekko, 1262 Third Ave., b/t 72nd & 73rd Sts.; 212-628-8400). For a suit with purpose, Shoshanna for Best & Co.’s sweet gingham one-piece benefits the Memorial Sloan-Kettering Cancer Center.

Now that’s getting into the swim of things.

LEARN
Identification Day
What: Kids bring found objects — shells, rocks, feathers, curios, bugs — to the Natural History Museum, and experts identify their treasures.
Why: Channel discovery.
When: Sat., 12:30-3:30 p.m.
Where: American Museum of Natural History, Milstein Hall of Ocean Life, Central Park West, at 79th St. (212-769-5100).

EAT
Big Apple Barbecue Block Party
What: The country’s best BBQ, live bluegrass, and support for Madison Square Park Conservancy.
Why: Dine ’n’ dance and perfect Dad’s Day dining.
When: Sat. & Sun., noon-6 p.m.
Where: Madison Square Park, b/t Fifth & Madison Aves., b/t 23rd & 26th Sts. (646-747-0584).

HEAR
Elizabeth Mitchell Sings
What: A mix of folk and rock celebrating nature.
Why: It’s a green day.
When: Sun., 2 p.m.
Where: The Jewish Museum, 1109 Fifth Ave., at 92nd St. (212-423-3200). Tickets at 212-423-3337 or online at museumtix.com.

DANCE
Kid Acts! Performance & Dance Party
What: A great mix of Music for Aardvarks, comic magic, and the spinning GrooveHoops.
Why: Petite performers welcome.
When: Sun., 2-4 p.m.
Where: Riverside Park South, Pier I, at 70th St. (212-408-0219).