Climate of the Sonoran Desert

The climate of the Sonoran Desert Region has long been used in promotional literature to attract new residents to southern Arizona. Before evaporative coolers and the invention of air conditioners summer heat discouraged the in-migration of permanent residents to some extent. Today, however, with much of the region having sunshine for up to 310 days per year (Dunbier 1968), climate continues to be a magnet to people seeking escape from cold, gray, humid, or snowy winters.

Largely surrounded by mountain ranges, the Sonoran Desert has a continental climate with great variability of both diurnal and seasonal temperatures (a subtropical continental similar to that of northern India according to Ellsworth Huntington (McGinnies 1981). These temperatures change with both elevation and latitude (IMADES), decreasing as one goes up in elevation or north in latitude. The continental effect is slightly modified around the Sea of Cortez. Air temperatures may vary from 32 to 36 degrees Fahrenheit and ground level temperatures as much as 100 degrees within 24 hours. Seasonal temperatures can range from below freezing in the northern portions of the region to a recorded high of 134 degrees in the shade at San Luis, Sonora in August, 1933 (Dunbier 1968).

The rainfall pattern is bimodal with a rainy season in both summer and winter. Average rainfall ranges from three to fifteen inches per year (Ingram 2000) with a general pattern of increasing precipitation as one moves eastward (Dunbier, 1968). Rainfall figures will vary depending on where one draws the region's boundaries. The pattern of rainfall is highly variable and include rainfall from tropical storms such as the one that led to severe flooding in 1983, rain that never reaches the ground, generally gentle rains of winter and the afternoon thunderstorms of late summer (Ingram 2000).

Related Links

• Basic description - from McGinnies, William G. 1976. An Overview of the Sonoran Desert.
• Buried Valleys and the Climatic Factor. Martin, Paul S. 1959. In Arid Lands Colloquia, 1958-1959. The University of Arizona. Tucson, Arizona.
• Climatic Fluctuations and Desert Vegetation Response in the Southwestern United States - Abstract from the 27th Annual Meeting and Symposium of the Desert Tortoise Council, March 22-24, 2002
• Climatology of Arid Lands. McDonald, James E. 1959. In Arid Lands Colloquia, 1958-1959. The University of Arizona. Tucson, Arizona.
• Health: The Land of Sunshine - select materials on the Southwestern United States from the pamphlet and printed ephemera collection of the University of Arizona Library Special Collections
• Meeting Drought on Southern Arizona Rangelands - Reynolds, Hudson G. 1954. Journal of Range Management 7(1):33-40. (pdf 1,834 KB)
• Vegetation Change and Arroyo Cutting in Southeastern Arizona During the Past Century: An Historical Review. Hastings, James Rodney. 1959. In Arid Lands Colloquia, 1958-1959. Tucson, Ariz.: University of Arizona Press.

"The climate, considered either in its relations to health and longevity, or to agricultural and mining labor, is unrivaled in the world. Disease is unknown, and the warmest suns of the Gila and Colorado River bottoms are less oppressive and enervating than those of the Middle States. The proportion of fine weather is greater than in any other part of the world I have visited or read of."

--(McCormick 1865. pp.4-5. in Zube and Kennedy 1990).