Tucson Winters Explained – Even the Locals will Learn Something New
In other places, April showers bring May flowers, but this is Tucson, where winter rains bring glorious spring wildflowers. Our winter days are mostly sunny with mild temperatures and clear skies. Many of our Sonoran Desert critters have gone south or are hibernating, though we do get the real kind of snowbirds escaping icy northern climes. As Westward Look Wyndham Grand Resort & Spa is in the Santa Catalina Mountain foothills, we do get frost on the plants. Occasionally, it has been known to snow in Tucson! (Blink and you’ll miss it.)
Climate change is altering the Sonoran Desert landscape, according to University of Arizona researchers. Winter rains are coming later, sometimes under colder temperatures. Annuals such as the popcorn flower and red filaree or storksbill that used to depend on early December winter rains are adapting to growing under colder conditions and flourishing. Other plant species that haven’t adapted, such as the wooly sunflower, are becoming less common.
According to the National Park Service, the Sonoran Desert gets winter rains when a low-pressure system forms over the western United States and pushes prevailing Pacific storms inland. Daytime temperatures are generally mild and because of the dry atmosphere (beware of static cling!) and relatively low vegetation cover, daytime heat reradiates the overnight air, making for chilly – but not too cold – evenings.
Even locals are apt to think that there are only two seasons: Rainy/hot and dry/cold. According to our friends at the Arizona-Sonora Desert Museum, there are five seasons:
- Summer monsoon or rainy season (early July to mid-September):
A tropical air mass adds humidity and moderates June’s extreme temperatures, frequent thunderstorms, main growing season for many of the larger shrubs and trees.
- Autumn (late September-November): Warm temperatures, low humidity, little rain, few species in flower, beginning of growing season for winter annuals in rare years with enough rain. Autumn and late summer occasionally receive heavy rains from the remains of Pacific hurricanes (tropical storms).
- Winter (December-February): Mostly sunny, mild days, with intermittent storms with wind, rain, and cool to cold temperatures. February is often warm and dry, like spring.
- Spring (early to late February through April): Mild temperatures; little rain; often windy; main flowering season for annuals, shrubs and trees. Winter annuals may bloom in February in warm, wet years.
- Foresummer drought (May-June): High temperatures, very low humidity, no rain in most years. May is very warm and often windy. June is hot and usually calm. There is little biological activity except for the flowering and fruiting of saguaro, foothill palo verdes and desert ironwood trees. Nearly every living thing is in basic survival mode until the rains arrive.
Rain or shine, we’re ready to show you the wonders of the Sonoran Desert and hope to see you soon at Westward Look Wyndham Grand Resort & Spa!