Will they be open on December 25??

I heard the south rim is open 24/7 365. And is not affected by the shutdown.

I am pretty sure most of the south rim is "closed" due to the shutdown. However, the road into the park may/most likely is open so you can drive. Not positive, just go and don't plan on using the restrooms or visitors center. Great views! I really doubt they will block the roads in, but you never know these days.