The weather can be great or it could not, it changes from day to day, I would give the Park a call before going. We wanted to go by it during a Spring Break a couple of years ago in March and a front was going through at the same time. We called and they told us about the fog and haze which could keep the vistas hidden. We did not go, we went to Tucson and Bisbee instead. We would have done the motel/hotel car trip for a short trip like we had planned. Hope it works out to be clear and sunny days for you when you are in the Southwest. If you get up by Flagstaff, the Sunset Crater is a nice area a nice loop drive by old ruines and just a neat drive. There is a very neat Navaho museum by Red Rock State Park as well, just east of Gallop, not to mention the short drive into the Petrified Forest Nat'l Park all on your way to the Grand Canyon area.
Happy Trails!
the DH