Dear Tom,

I notice there is often a huge temperature difference between Phoenix, Arizona, and Flagstaff. Recently, Flagstaff recorded a low of 20 degrees and Phoenix had a high of 106, but the cities are only about 123 miles apart. How can that be? —

Jack Hardekopf, Aurora

Dear Jack,

The great temperature differences between Phoenix and Flagstaff are explained by the differences in elevation of the two cities. Phoenix sits at an elevation of 1,086 feet and Flagstaff at 6,909 feet. The distance between the two cities is 123 miles (Flagstaff lies north of Phoenix), but the elevation difference is 5,823 feet. Average annual temperatures at the two cities are 43.8 degrees at Flagstaff and 75.1 at Phoenix. Flagstaff is a snowy city, receiving an annual average of 101.7 inches; Phoenix, 0.0 inches.