What can we play on a rainy day?

Today we reintroduced Rohan to his sandbox in the garage after a two month hiatus and he greeted it with glee. It is a nice rainy day, kind of like being back in Oregon. It's in the high 40s and drizzling. A good one for an inside outside kind of activity. Our garage is the defacto location for those kinds of activities. We have a sandbox, a tent, a chalk board, a whiteboard, and last but not least, a bubble machine