Jingle Bell Walk
Long Island Maritime Museum
West Sayville
$8; children 5 and under free 
All kids participating in this walk around the museum grounds receives a jingle bell and a stocking, and stocking stuffers along the course of the walk. Afterward, there will be hourly readings of Polar Express and holiday treats, and Santa will be arriving by boat. Proceeds benefit the museum and Shelter Link, a group supporting the Islip Town Animal Shelter.

MOMIX Botanica
Tilles Center for the Performing Arts
Greenvale 
516-299-3100
$15, $25
The little ones' eyes will grow as big as the gorgeous plants and flowers dancing across the stage, as they watch this unique company of dancers bring a magical garden to life.

9th Annual Reenactment of the Flying Santa
Fire Island Lighthouse
Fire Island 
631-321-7028
Free 
The Fire Island Lighthouse on the Great South Bay was an important landmark for ships coming into the New York Harbor. Fifty years ago a biplane arrived at the Fire Island Lighthouse and dropped a surprise bag of presents for the lighthouse keeper and his family. To commemorate this event a biplane circles the lighthouse each year and Santa appears at the top of the light before descending to meet the children, hear their wishes, and be photographed. Godfried Mahler, the lighthouse keeper who received the wonderful gifts, will also be present to tell the tale. This event is popular so arrive early
 

Montauk Point Seal Hike
Montauk Lighthouse Concession Stand
Montauk
631-668-3781
adults $5, children 7-12 $3
Go on a hike to see all the different types of seals that inhabit Montauk. Harbor and grey seals are most common, but sometimes rarer harp or ringed seals can be seen. The hike, organized by the NYS Parks and Recreation Dept, begins at the Montauk Lighthouse concession stand and lasts approximately 2–3 hours; warm clothing and comfortable shoes are essential. Registration is required, and the hikes fill up quickly. Hikes are held on weekends throughout the winter and early spring until late April. To register, call 631-668-3781 or 631-668-5000. For the hike calendar, click here. There is a $8 fee to park in the Montauk State Park parking lot.

CRESLI Seal Walk
 Cupsogue Beach County Park
Westhampton
631-244-3352
suggested contribution: adults $5, children 12 and under $3
Winter is the time to see seals on Long Island. Grey and harbor seals are increasingly common and in recent years arctic species such as harp, hooded, and ringed seals have been spotted. CRESLI (the Coastal Research & Education Society of Long Island) runs 1.2-mile-round-trip seal-spotting walks on weekend dates from December through early May. The walks are suitable for children and last about 1–2 hours. They depart from the area near the fence at the western end of the parking lot. Meeting times are 15 minutes prior to departure. Click here for a full schedule and to make reservations.

Saturday and Sunday:

Sanctuary Traditions
Theodore Roosevelt Sanctuary & Audubon Center
Oyster Bay
516-922-3200
members $20 per family / nonmembers $28 per family 
This family event features nature walks, holiday storytelling and crafts, music, refreshments, activities to help wildlife, and a visit from Santa. Preregistration and prepayment are required.
 

Sunday:

Festival of Lights!
Long Island Children's Museum
Garden City
$3 with museum admission (LICM members $2)
Celebrate Hanukkah with the Long Island Children's Museum. Children will earn about the history and traditions of the Festival of Lights, and make their own menorah.

Holiday Candlemaking Workshop
Cold Spring Harbor Whaling Museum
Cold Spring Harbor
631-367-3418
children $8 (members $4)
Find out how people lit their homes in the 1800s, and roll your own honeycomb beeswax candle to light at home.