I took a one-week tour of northern Arizona and southern Utah, beginning with the tourist Mecca of the Grand Canyon. My visit was on December 28, 2008. At this time of year, temperatures are in the low 40s in the afternoon - much colder in the early morning. Crowds are relatively light, although some of the main parking areas fill up quickly. I entered through the eastern entrance (at Desert View) and drove the entire 25 miles to the other end. Such a drive would not be possible in the summer months!!