Sonoran Desert

The Sonoran Desert (Spanish: Desierto de Sonora) is a hot desert and ecoregion in North America that covers parts of the northwestern Mexican states of Sonora, Baja California, and Baja California Sur, as well as part of the Southwestern United States (in Arizona and California). It has an area of 260,000 square kilometers (100,000 sq mi).

In phytogeography, the Sonoran Desert is within the Sonoran floristic province of the Madrean region of southwestern North America, part of the Holarctic realm of the northern Western Hemisphere. The desert contains a variety of unique endemic plants and animals, notably, the saguaro (Carnegiea gigantea) and organ pipe cactus (Stenocereus thurberi).

The Sonoran Desert is clearly distinct from nearby deserts (e.g., the Great Basin, Mojave, and Chihuahuan deserts) because it provides subtropical warmth in winter and two seasons of rainfall (in contrast, for example, to the Mojave's dry summers and cold winters). This creates an extreme contrast between aridity and moisture.

It is asserted (though possible contrary evidence exists) that the Sonoran is the joint hottest desert on Earth.

Location

The Sonoran desert wraps around the northern end of the Gulf of California, from Baja California Sur (El Vizcaíno Biosphere Reserve in central and Pacific west coast, Central Gulf Coast subregion on east to southern tip), north through much of Baja California, excluding the central northwest mountains and Pacific west coast, through southeastern California and southwestern and southern Arizona to western and central parts of Sonora.

It is bounded on the west by the Peninsular Ranges, which separate it from the California chaparral and woodlands (northwest) and Baja California desert (Vizcaíno subregion, central and southeast) ecoregions of the Pacific slope. The Gulf of California xeric scrub ecoregion lies south of the Sonoran desert on the Gulf of California slope of the Baja California Peninsula.