A rainbow shines over saguaros against a stormy sky.
A rainbow shines over saguaros as it storms during Monsoon Summer.

NPS Photo


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A chart containing different average temperatures during months of the year
This chart shows the average high's, low's and rainfall in each month.

NPS Photo

Five Seasons of Life and Rejuvenation

The Sonoran Desert is the wettest desert in the world, receiving anywhere from 3-15 inches of rain each year, continually rejuvenating and sustaining life in one of the lushest deserts in the world. This beautiful desert has five distinct seasons with unique weather patterns which the life residing here has adapted to and thrives in. Below is information about what to expect during each season, and a temperature chart displaying the monthly averages.

Dry Summer

Dry summer spans from mid-April through mid-July, and is the hottest time of the year. Temperatures usually stay well above 100F during the day, and over 70F at night. Nights may be well warmer, and humidity is usually less than 10 percent.

This is the season many cacti produce flowers and fruits, including the Saguaro and Organ Pipe Cactus. Many nocturnal animals such as bats and moths come to feast on what the cacti provide this time of year, pollinating the plants and spreading their seeds across the landscape.

Monsoon Summer

The wettest time of the year in the Sonoran Desert in from mid-July through mid-September. Rising humidity and temperatures combine to create monsoon thunderstorms that douse the dry earth across the desert, providing much needed water to the life residing there. Temperatures stay well above 100F during the day and 70F at night, and the humidity drastically increases, giving the Sonoran Desert an almost tropical feel.

This time of year is amazingly beautiful and lush! It's a wonderful time to encounter desert rainbows, blooming plants and cacti, butterflies, and a multitude of amphibious life (such as the Sonoran Desert toad) emerging from washes and tinajas strung throughout the desert. This can also be a precarious time to visit due to afternoon thunderstorms bringing hard rains that fill the washes quickly, creating flash floods. Make sure to check the weather daily during this season.


Milder temperatures and a drier climate arrive starting mid-September and last through the end of October. The monsoons fade to an end. Temperatures drop into the mid-80s and the humidity falls drastically.

This time of year has pleasantly warm days and warm, mild nights. The washes and tinajas begin to dry once again, and plants begin to loose their leaves and flowers. Fall colors from dry grasses and fallen ocotillo leaves intermix with the evergreen cacti.


Mild days and cool nights arrive in November and last through January. Temperatures in December and January may fluctuate drastically day to day, from high 60's to low 50's during the day, and low 40's to below freezing at night. Mid-December through January brings cool winter rains, rejuvenating the landscape and bringing water for spring flowers.

Mild temperatures make this a popular season to visit the monument for hiking and camping. Experiencing rain in the desert is a thrill many visitors enjoy, even if it may dampen their hiking plans for the day. The night sky is clear this time of year and makes for spectular nighttime viewing of the Milky Way and an endless sea of stars.


February through mid-April is springtime in the desert, bringing warming temperatures and brighter skies. Temperatures begin rising to the mid-70s and 80's and the rains cease until the monsoon season returns.

Colorful wildflowers begin springing out across the desert floor and canyons as early as February, and continue to bloom through mid-April. Butterflies, moths, hummingbirds, and other flower loving animals make their appearance to enjoy the beautiful blooming bounty.

Last updated: May 23, 2023

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10 Organ Pipe Drive
Ajo, AZ 85321



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