I get that kids can be outside when it rains, but there's just stuff you can't do. We take our son to the park every day. We're not gonna have him crawl around in wet sand or go down flooded slides. Our apartment is too small for him to be entertained just staying in all day every day.
Yes, that stuff you won't be able to do but being able to go for hikes during winter and not freeze your ass off is fantastic. We'd do a bunch of hikes, walk around the zoo, go to museums, etc... a lot. I mean, look at the weather, it's going to be in the low 50's for the next two weeks. Also, a "rainy" day typically means that it drizzles a little bit in the morning and that's it.