I like clothespins. Work on fine motor skills and math!
Snowflake stamp art activity for kids
Ice volcanoes are easy to make and a fun science and play activity for kids of any age
Melting Elsa's Frozen Hands Activity - Happy Hooligans
DIY crystal snowflake | Science Fair Projects from Pinterest - Parenting.com
Popsicle Stick Snowflake Craft - Winter Craft - Preschool Craft
Not the direction that I'm going with my girls play area, but definitely creative and a great idea.
Ice water and shaving foam