You can get winter weather in So. Arizona around Christmas & New Years while March is likely to be beautiful - like today. I'd plan on spring break if you can. March here really is spring.

December can be pretty chilly, but it's still usually great hiking weather.

Today in Tucson is spectacular...supposed to be 85 tomorrow.

It can be beautiful at Christmas time or cold and grey. march is safer. Both Saguaro National Parks, E and W, are beautiful.
Sabino Canyon will honor a National Park Pass if you have one.

Oh wow, thanks for the info on Sabino honoring the park pass. I wouldn't have known that.

Is there any reason not to go Dec 28,29,30,31, and Jan 1? Or should I just plan on going Spring Break?

One big advantage of going in March is that typically the desert is blooming with acres of wildflowers, mainly Mexican Gold poppies but also dozens of other colorful flowers and some early cactus (the saguaros bloom later). The biggest disadvantage is higher cost, mainly because 15 of the major league baseball teams hold their spring training in the Phoenix area in March, typically selling 1.5 million tickets for Cactus League games, so airfare is more, resorts are busier and rental cars cost more.

In December nothing is blooming but typically the weather is pretty good for hiking, maybe sunny and mid-60's around Tucson (more likely 75-80 and sunny in mid-March). If the cost difference isn't too high I'd much rather go in March. For sure more chance of rain or overcast in Dec, but still should be OK weather in Dec.

You also had a post about GC hiking (rim to rim); March is the perfect time to go down to the river and back from the south rim because usually there is little ice on the trail on top and temps are pleasant on the bottom, so you avoid the heat problems of summer. You could do that hike with just a one night stay on the south rim ...

Bill_h,
I've thought about the GC at springbreak and even in the Winter(knowing the thoughts on snow and crampons, etc).
I don't know that I would hike to the bottom more than once, so for some reason I have it in my mind I must do rim to rim. Plus,I haven't been to the North Rim.

I would be doing Tucson with my wife and daughter. Hiking the GC would be with my nephew(age 13-so he would be 14 next year). My daughter might be up for the GC too, but she isn't sure. She had a very serious back surgery June 2010 and not sure that a serious hike like that would be the thing to do. We are doing some pretty good hikes this summer, so we'll see how she does. She is 18 years old. My wife teaches HS and she might go with myself and nephew-she wouldn't hike to the bottom though. He attends a different school, so sometimes the breaks aren't the same time.

I have several options, just trying to decide. Time is much more of an issue than money. I can only take long weekend trips. Not complaining, I get to take several long weekend trips each year, but just can't go on the long week or two trips.

Thanks for all the info

The way Christmas falls was allowing me an extra day for that long weekend. So, I was debating on going to somewhere. I had planned on going to Miami-however, Airlines Awards or just buying outright the prices and points are rediculous. Anyway, Tucson was a bargain for some reason. So, I was debating on that. I think I will save it for spring break though. I like to go at the best times. I can always do something closer to home(which is Oklahoma, btw)-the Buffalo River area is really nice here in the winter-lots of waterfalls.

I would like to see all the National Parks. I am up to 29 of them and plan on seeing 4 new ones this summer. So, I am debating on taking my nephew to the GC or going somewhere that I haven't been before. He has never seen the GC and I really want to hike to Phantom or Havasu. If I do Havasu, we would obviously stop for a day at the south rim too.

If late December works better for your schedule for a Tucson visit, go for it. There are no guarantees on the weather any time in Winter or early Spring. Yes, it is beautiful here right now. But I have also seen cold, windy, rainy, and even snow in Tucson in March and even early April.