When it rains you just bundle your kids up and send them out in the rain. It doesn't usually rain hard here. And as long as it's not freezing or blowing really hard the kids don't care. You will have extra laundry to do, but it seems most kids really like the mud so they don't mind.
There are also places like the Children's Museum, OMSI, Indoor Park Co-ops, the Library for story time and activities, and Portland Parks and Rec for great indoor classes.
It doens't rain hard here so it's really not that bad. By March I'm tired of the extra mud my kids track in the house. But many of my friends have said that my children have an higher affinity for mud that most kids. They are special that way.
