Indoor
Keep kids occupied on a rainy day by teaching them board games or uncomplicated card games, such as Go Fish. Help your child forget he's inside by playing gentler versions of outdoor games. Play indoor baseball using an empty gift-wrap roll as a bat and a balloon as a ball. Take turns throwing and hitting with your child. Help him create a secret fortress by pushing chairs together and draping sheets over the chairs. Help him bring toys, pillows, flash lights, books and stuffed animals into the tent and have him pretend its a secret hideout.
Outdoor
Let your child use colorful chalk on your driveway. Have him print his name, make designs or color freely. Take turns tracing each others shadows and coloring in facial features, clothes and hair. Play a soft game of catch using a light plastic ball, or grab a plastic bat, designate bases and simulate a game of baseball. Catch butterflies with a butterfly net and then set them free or buy a bubble set and blow bubbles.
Educational
Cut various colors of construction paper into two pieces that are roughly the size of index cards. Split the cards up between you and your young child so each of you have a set including one of each color. Show a card to your child and say, "I have a green card, will you hand me the matching card?" He will enjoy being able to match colors and will eventually be able to match them on his own. Make every activity a counting activity to help your child learn basic math and counting. Count how many steps you climb together, how many dishes you lay out for dinner, how many doors and windows are in the house, and so on. He will be learning math without even realizing it.
Online
Children can play a variety of free action, adventure, maze games and many others online. Exploring games on the computer will help your child will build necessary computer skills. Help him use the mouse, keys and navigate websites until he feels comfortable doing it on his own. See the Resources section for links to kid-friendly sites from Lego and Nickelodeon.