Sometimes, you have get it straight from the source. This list came (mostly) from a kindergartner who, in his short life, has spent more than a few days stuck in the house because of rain, snow, or sickness. Check with your child and come up with your own list!
2. Do jobs. (For real, he said that.)
3. Make a play house with furniture, bed sheets, and pillows.
4. Build something with big blocks or empty boxes: a tower, a zoo, an airport, aircraft, helicopter, or a big house.
5. Eat popcorn and watch a movie. Mommy or daddy can help make a cozy place on the floor where the family can sit back and enjoy the flick.
6. Make and eat a special snack.
7. Bring in snow from outside and see how long it takes to melt.
8. Make snow candy.
9. See what new things you can build with Legos, stacking blocks, Lincoln Logs, or whatever kind of building blocks you have in the house. Mega Bloks are connecting blocks that come in various sets for children. These are great for developing creativity and fine motor skills, and just may keep your elementary-age child entertained for quite awhile, though these aren't as durable and secure when connected as Legos.There are small very small pieces in some of the sets, so watch out for younger siblings. Mega Bloks are a less-expensive option than similar toys, and have a large selection of themed building sets to choose from.
10. Have a snowball fight. (You have to go outside even when it's cold. Even for just a bit.)
11. Watch the weather just for fun. All those radar graphics are really cool.
12. Make a fort. You can use a big blanket, but if you really want to get functional, check out the the Fortamajig from The Happy Kid Company. This contraption is a simple tarp, complete with Velcro straps made to hook on everything from chairs and table legs, to stair rails and doorknobs. The Fortamajig totally solves the age-old problem of your roof caving in because the quilt you were using to make a fort slipped off the furniture (from not being securely attached). It can also be used outside on nice-weather days since the straps can also hook to tree branches, porch posts, and swing sets.
13. Pull out books you haven't read in a long time, and cuddle up for a read-aloud session.
14. Put together an obstacle course. Use tables to walk around, chairs to crawl under, tape on the floor to walk on, bean bags to hop around, and other ideas you come up with.
FTC Disclosure: I received a Blok Squad set and a Fortamajig to play with (I mean, for my kid to play with). The opinions in this article reflect his/my/our honest experience with these products.