is the city museum close if it rains?

Only the roof and outdoor area but there still is pleanty of things to do inside.

Only the roof is closed during the rain.

Inside has alot of activites

Also, the inside and outside are priced separately. If it is raining you can opt to only pay for the inside, and if things clear up that day, you can go back and buy the outside pass (for an extra $4-5 I think - It's worth it).