What Qualifies as Desert?

Posted by Robert Dailey Sep 7, 2006

For the desert gardener, particularly in the southwestern U.S., growing seasons can be intricate and complex.

Desert gardeners in Phoenix, Arizona, for instance, experience summer lows of 75 degrees F and highs in the 100's.

Santa Fe, New Mexico, a little over 300 miles as the crow flies northeast of Phoenix, sees summer lows in the mid-50's and highs in the low 90's.

Technically, deserts are defined as areas which receive less than 10 inches of precipitation annually.

Phoenix, which sits at 1,085 feet above sea level, receives about eight and a half inches of precipitation per year. Santa Fe, at 7,200 feet above sea level, receives 14 inches per year. Phoenix is in the Sonoran Desert and the rainfall it receives qualifies it well within the desert definition. But tell that to the gardeners in Santa Fe, Denver, and elsewhere.

Denver, Colorado, which is lower than Santa Fe, but farther north, experiences even colder temperatures and receives about two inches more of precipitation than does Santa Fe.

Las Vegas, Nevada (at 2,178 feet) receives less than 5 inches of precipitation per year, and San Diego (at 40 feet) receives just less than 12 inches.

Areas of the Colorado Plateau, which encompasses parts of eastern Colorado, western Utah, northwestern Arizona and northeastern and central New Mexico, receive varying amounts of precipitation.

Even areas of Canada, which few people identify as "desert", receive small enough amounts of precipitation per year to qualify. Calgary, Alberta, for instance averages only 15.7 inches of precipitation per year, a little less than Denver, and a little more than Santa Fe.

Compare this to other major North American cities. Montreal, Chicago, St. Louis and Mexico City all receive over 30 inches per year.