I love riding in Tucson. It may be quite cool in the early morning, even in late Dec. The temps are in the 70-80s by 10am, and quite pleasent until after sundown. If some occasionally stiff wind aren't against your rules, I suggest a 'warm' ride after 12pm, heading south from anywhere in Tuscon, which will leave nice tail winds on your return late in the afternoon.
Besides the sunsets in the winter are still amazing at times.
