White Sands National Monument is located in southern New Mexico at the northern end of the Chihuahuan Desert. This is North America's largest desert, the majority of which is located to our south in Mexico. This desert region amounts to about 175,000 square miles, stretching some 1200 miles south from Alamogordo, New Mexico, to the the Mexican state of San Luis Potosi. The elevation ranges from near 1,000 feet above sea level along the Rio Grande in Texas to 10,000 feet in the mountainous regions of Mexico, with a large portion found above 4,000 feet. Winters are cool, with nighttime temperatures falling below freezing (occasionally below 0 degrees) an average of 100 times per year in the northern latitudes and climbing as high as 122 degrees F. in some regions.
The Chihuahuan desert differs from the Sonoran and Mojave deserts by receiving more summer rain during monsoon thunderstorms and by colder winters that can drop below 0 degrees F. An ecologically significant factor of the Chihuahuan desert and the monument is probably the number of days below freezing. In the last twelve and one-half years, there have been no temperatures at WSNM below zero degrees F.