Natural wonder North America
Sonoran Desert
The Sonoran Desert is a hot desert in Mexico and the United States. It is full of cactus plants and animals.
The Sonoran Desert covers about 260,000 square kilometers of northwestern Mexico and the southwestern United States. It gets rain in two seasons each year, and the US Geological Survey says it is considered the most biologically diverse desert in North America. It is home to the saguaro cactus.
The Sonoran Desert occupies about 260,000 km² of northwestern Mexico and the southwestern United States, more than two-thirds of it in Baja California and Sonora. A subtropical desert with winter rains and summer monsoon storms, it is thought to have the greatest species diversity of any desert in North America (National Park Service).
Photo: Tomascastelazo, CC BY-SA 4.0, via Wikimedia Commons
Discover the Sonoran Desert
The Sonoran Desert is in Mexico and the United States. Most of it is in Mexico.
In this photo, yellow flowers and gray bushes cover the ground in front of rocky mountains.
The Sonoran Desert covers about 260,000 square kilometers. The National Park Service (NPS) says more than two-thirds of it is in the Mexican states of Baja California and Sonora; in the United States it covers much of southern Arizona and small parts of southeastern California.
This photo by Tomascastelazo, taken in October 2015 near San Carlos in Sonora, Mexico, shows the desert in its blooming season: yellow flowers, round gray shrubs and a jagged rocky range.
The NPS Sonoran Desert Network gives the desert about 260,000 km² (100,387 sq mi), including the southern half of Arizona, southeastern California and most of Sonora and Baja California, between about 23°N and 30°N. It is bounded on the north by the Mogollon Rim and grades into the Chihuahuan Desert to the east and the Mojave to the west.
The hero photo, by Tomascastelazo (CC BY-SA 4.0, a Commons featured picture), shows San Carlos, Sonora, in the blooming season on 18 October 2015.
- Area
- about 260,000 km²
- Where
- northwestern Mexico and the southwestern United States
- Plant species
- more than 2,000
A desert with two rainy seasons
Rain comes to this desert twice a year: in winter and in summer.
Summer storms can be loud and strong.
The USGS calls the Sonoran Desert the only desert in the world with two rainy seasons each year. Gentle rains fall in winter, around December and January, and powerful monsoon thunderstorms come in summer, around July and August.
Its rocks range from about 2 billion years old in Arizona to volcanic activity in the Pinacate region around the year 700.
The NPS lists the reasons for the desert's diversity: a subtropical climate, its continental setting, bimodal precipitation (frequent low-intensity winter rains in December and January and violent summer monsoon thunderstorms in July and August), varied geology and wide-ranging topography.
Its sedimentary, igneous and metamorphic rocks span 2-billion-year-old Precambrian outcrops in Arizona to relatively recent volcanism, around 700 CE, in the Pinacate region.
Cactus and creatures
The saguaro is a tall cactus that grows only in this desert.
Many birds, lizards and other animals live here too.
The NPS counts at least 60 kinds of mammals, more than 350 kinds of birds, 20 amphibians, about 100 reptiles and about 30 native fish in the Sonoran Desert, plus more than 2,000 kinds of plants.
The saguaro cactus grows only in the Sonoran Desert. The USGS says it gives many animals shelter, food and places to nest.
The NPS says the Sonoran Desert is thought to have the greatest species diversity of any desert in North America: at least 60 mammal species, more than 350 birds, 20 amphibians, some 100 reptiles, about 30 native fish and more than 2,000 plant species, with lifeforms from columnar cacti to conifers and Gila monsters to pygmy owls.
The USGS notes that saguaro cacti (Carnegiea gigantea) are found only in the Sonoran Desert and provide shelter, food and nesting sites for many animals.
From cactus flats to pine forests
The desert has low, hot flats and high mountains.
On the tallest mountains, pine trees grow.
The NPS says the Sonoran Desert's landscapes range from hot desert, where frost is nearly absent, to cold conifer forests on high mountains.
At Saguaro National Park in Arizona, the USGS describes low desert scrub of shrubs and cacti, and higher up grassland, oak woodland and pine forest.
According to the NPS, the desert's landscape diversity rivals that of any other land ecoregion, with nearly all of the planet's biomes represented, from cold conifer forests to hot deserts where frost is nearly absent and rain rare. It is a continental-scale transition between the tropics and the temperate zones of western North America.
At Saguaro National Park, the USGS describes desert scrub as the driest, lowest community (about 1,000-2,500 ft), dominated by shrubs and succulents, with grassland, oak and pine-oak woodland and conifer forest higher in the Rincon Mountains.
Visiting safely
The desert gets very hot. Bring water, a hat and sunscreen.
When it rains, stay out of dry riverbeds and canyons.
The NPS at Saguaro National Park says summer days regularly reach well over 100°F and recommends sunscreen, water, hats and sunglasses. When the high is between 95°F and 110°F, hikes should end by 10 a.m., and above 110°F, visitors should not hike.
Summer monsoon rains can send water rushing down dry washes and canyons as flash floods. Stay out of canyons when rain is expected, and if caught, climb up high.
Saguaro National Park advises turning around before half your water is gone, finishing hikes by 10 a.m. when highs are 95-110°F and not hiking above 110°F; summer daytime temperatures regularly reach well over 100°F.
During the monsoon (June 15 to September 30), afternoon storms over the mountains can fill washes, drainages and canyons, sometimes as flash floods. The NPS says to avoid canyons when rain is expected and, if caught in a flash flood, to climb as high as possible.
Amazing facts
-
This desert gets rain twice a year, in winter and in summer!
The USGS calls the Sonoran Desert the only desert in the world with two rainy seasons each year.
USGS: the Sonoran Desert is the only desert in the world that experiences two rainy seasons per year.
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The saguaro cactus grows only in the Sonoran Desert.
Saguaro cacti grow only in the Sonoran Desert, and they give many animals food, shelter and nesting places.
Carnegiea gigantea is found only in the Sonoran Desert, where it provides shelter, food and nesting sites for many animals (USGS).
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A flash flood can sound like wind in the trees.
The NPS says flash floods are known to sound like wind blowing through trees. If you are caught in one, climb up high!
Saguaro National Park notes flash floods are known to sound like wind blowing through trees; the advice is to go up, as high as you can.
Words to know
- desert
- a place that gets less than 10 inches (25 cm) of rain a year, where more than that amount of water could evaporate in a year
- monsoon
- a season of heavy rains and storms brought by a shift in the winds
- saguaro
- a tall cactus that grows only in the Sonoran Desert
- wash
- a dry riverbed that fills with water after heavy rain
- flash flood
- a sudden flood that rises very quickly after heavy rain
Discovery challenge
-
How many rainy seasons does the Sonoran Desert have each year?
How many rainy seasons does the Sonoran Desert get each year?
How many rainy seasons a year make the Sonoran Desert unique, according to the USGS?
- Two
- None
- Five
Show the answer
Two
Two: one in winter and one in summer.
Two: winter rains and summer monsoon storms.
Two: December-January winter rains and July-August monsoon storms.
-
Which cactus grows only in this desert?
Which cactus is found only in the Sonoran Desert?
Which cactus, Carnegiea gigantea, does the USGS say grows only in the Sonoran Desert?
- The saguaro
- The pine
- The palm
Show the answer
The saguaro
The saguaro.
The saguaro cactus.
The saguaro, which gives many animals food, shelter and nest sites.
-
In which countries is the Sonoran Desert?
Which two countries share the Sonoran Desert?
Between which two countries does the NPS place the Sonoran Desert, with more than two-thirds in one of them?
- Mexico and the United States
- Chile and Peru
- Egypt and Libya
Show the answer
Mexico and the United States
Mexico and the United States.
Mexico and the United States; most of it is in Mexico.
Mexico (over two-thirds, in Baja California and Sonora) and the United States.
-
What should you bring to the hot desert?
What does the NPS at Saguaro National Park recommend bringing in summer?
Which items does Saguaro National Park call incredibly encouraged in summer heat?
- Water, a hat and sunscreen
- A heavy winter coat
- Nothing at all
Show the answer
Water, a hat and sunscreen
Water, a hat and sunscreen.
Sunscreen, water, hats and sunglasses.
Sunscreen, water, hats and sunglasses; turn back before half your water is gone.
-
If a flash flood comes, where should you go?
What does the NPS say to do if you are caught in a flash flood?
What is the NPS advice if caught in a flash flood?
- Climb up high
- Go down into the canyon
- Lie down in the wash
Show the answer
Climb up high
Climb up high, away from the water.
Go up and climb as high as you can.
Go up: climb as high as you can to avoid the water.
Nearby places
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Phoenix
Phoenix is the capital of Arizona, in the southwestern United States. It lies in the northeast of the Sonoran Desert, near where the Salt and Gila rivers meet, and it grew from a farming community that reused old Native American irrigation canals. The Census Bureau estimated 1,665,481 people in Phoenix in 2025.
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Natural wonder
Colorado River
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Grand Canyon
The Grand Canyon is a huge, steep-sided canyon in Arizona carved by the Colorado River. It is about 447 kilometers long and, on average, 1.6 kilometers deep, and its walls show layers of rock almost two billion years old.
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Landmark
Hoover Dam
Hoover Dam is a huge concrete dam across the Colorado River, on the border between Nevada and Arizona in the United States. Built from 1931 to 1936, it holds back Lake Mead, protects farms and towns from floods, stores water for cities and farms, and makes electricity.
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City
Los Angeles
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Antelope Canyon
Antelope Canyon is a slot canyon near Page, Arizona, on the lands of the Navajo Nation. Its walls of Navajo Sandstone are smooth and wavy because water from flash floods rushed through the narrow passages again and again, wearing the rock away. Visitors may enter only with a guided tour.
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Hollywood Walk of Fame
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Bryce Canyon National Park
Bryce Canyon National Park, in southern Utah, is not really a canyon. It is a row of giant bowls, called amphitheaters, carved into the edge of a high plateau and filled with colorful rock spires called hoodoos. The park says it has the largest collection of hoodoos in the world. Ice and rain shaped them from rocks first laid down in an ancient lake.
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Atacama Desert
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Sahara
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Country
Mexico
Mexico is a large country in southern North America, between the Pacific Ocean and the Gulf of Mexico. It has smoking volcanoes, ancient cities built by the Maya and other peoples, and about 132 million people, many of them in and around Mexico City.
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Country
United States
The United States is a large country in North America made of 50 states, from icy Alaska to the warm islands of Hawaii. It has the Grand Canyon, the Mississippi River and Yellowstone, and about 342 million people live there.
- Watch Geography What makes a desert? A desert is any place that gets very little rain or snow, usually less than about 250 millimeters a year. Deserts can be hot, like the Sahara, or freezing cold, like Antarctica, the driest continent. They form where winds, mountains or cold ocean currents keep rain away.
- Watch Geography Monsoons A monsoon is a seasonal change in the direction of a region's strongest winds. In South Asia, the summer monsoon blows warm, wet air in from the Indian Ocean and brings months of heavy rain, while the winter monsoon blows dry air from the land. About three-quarters of India's yearly rain falls in the monsoon season, so farms, wells, rivers and power stations all depend on it.
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Natural wonder
Chihuahuan Desert
The Chihuahuan Desert is the largest desert in North America, the U.S. National Park Service says, and more than 90 percent of it lies in Mexico. It has hot summers, cold winters and summer storms, and it is home to as many as 3,500 kinds of plants, including nearly a quarter of the world's cactus species.
For parents & teachers
What children will learn
- Locate the Sonoran Desert in northwestern Mexico and the southwestern United States.
- Explain what makes the desert's two rainy seasons unusual.
- Name the saguaro cactus and how it helps other animals.
- Know how to stay safe from desert heat and flash floods.
Recommended ages: 3 to 17 · About 15 minutes
Talk about it
- Why might rain twice a year help so many plants and animals live in a desert?
- Why might a flash flood happen even where it is not raining?
- How can one plant, like the saguaro, help many animals?
Try at home or in class
- Pour a cup of water onto hard, dry soil and onto loose soil outdoors and watch which one soaks it up and which one lets it run off, like a desert wash.
- On a map, find Sonora, Baja California and Arizona, and shade the area the Sonoran Desert covers.
Key vocabulary: desert, monsoon, saguaro, wash, flash flood
Where these facts come from
- Wikidata , Wikimedia Foundation (CC0 1.0)
- Sonoran Desert Network Ecosystems , US National Park Service, Inventory & Monitoring
- Ecology of Saguaro National Park , US Geological Survey
- The Sonoran Desert (Casa Grande Ruins National Monument) , US National Park Service
- Weather, Saguaro National Park , US National Park Service
- File:San Carlos Sonora landscape.jpg , Wikimedia Commons
- Natural Earth vector data , Natural Earth (NACIS) (Public domain)
- Wikimedia Commons , Wikimedia Foundation (Per file (public domain, CC0, CC BY or CC BY-SA); see each media record)
Checked, not yet human-reviewed. Last updated November 1, 2026. Spotted a mistake? Tell us.