Rough Seasonal Schedules for Our Area

Note: Our "Climate" data are taken mainly from Harold Elliott's weather station, reflecting the Cascabel area near the river -- see this link for more details. "Flowerings" data are taken mainly from William G. McGinnies, "Flowering Periods for Common Desert Plants: Southwestern Arizona", published by The University of Arizona College of Agriculture, Office of Arid Lands (as a folding single sheet; no date given; based on 20 years of research from 1966 to 1985). See this link for further details on McGinnies' listings of specific plants, which covers a broader area of the Sonoran Desert. Rosanne Hanson & Jonathan Hanson, 1996, Southern Arizona Nature Almanac, Tucson: University of Arizona Press, was a valuable reference for compiling these lists, and their essay "Sonoran Desert Natural Events Calendar", in Steven Phillips and Patricia Comus, eds., 2000, A Natural History of the Sonoran Desert, pp. 19-28, Arizona-Sonora Desert Museum Press, Tucson, was also useful.


Image at left: rare snows on our lands, terrace overlooking the San Pedro River Valley, January 2007

CLIMATE: Average high temp. = 67 F; average low temp. = 34; average temp = 51; average rain = 1.27"; average maximum wind = 26 mph. Freezing is very likely this month, and many of the deciduous trees will drop their leaves. (This is usually our coldest month, when the hardest freezes may occur.)

FLOWERINGS: Not much of a flowering period, but rains now are very important for future flowerings. (Length of flowering season for spring annuals depends on winter rain. It may run from 30 to 60 days.) Annuals and grasses will sprout new growth. Cottonwoods may show new leaves, blossoms.

RIPENINGS: Desert mistletoe berries are ripe. (Many will be found in Paloverde and Mesquite groves.)

FAUNAL ACTIVITIES: Spiny Lizards may appear on warm days. Male Phainopeplas perch in mistletoe-laden trees awaiting females attracted to their favorite food; mockingbirds, curve-billed thrashers, and cactus wrens are breeding too. Harris Hawks may begin laying their eggs. Sandhill Cranes are present on the Willcox Playa. Packrats begin their mating seasons, and White-tail and Mule Deer are in rut.


Image at left: Hot Springs Canyon viewed from the Red Trail, February 2004. Sycamore trees showing early signs of life.

CLIMATE: Average high temp. = 71 F; average low temp. = 37; average temp. = 54; average rain = 1.31"; average maximum wind = 31 mph. Temperatures warm somewhat from the January low.

FLOWERINGS: Cool weather flowering season begins by the end of the month: Sand verbena, bladderpod mustard, evening primrose, loco weed, Parry penstemon, owl-clover. Some deciduous trees may bloom.


FAUNAL ACTIVITIES: Hummingbirds are migrating north; Gila woodpeckers mark their territories with hammering sound. Great Horned Owls are also breeding. Antelope Squirrels bear young in underground nests, and some lizards (mainly small ones) may be seen. This is deer-mating season.


Image at left: flowering hillside in lower Hot Springs Canyon, March 2001.

CLIMATE: Average high temp. = 77 F; average low temp. = 40; average temp. = 58; average rain = .93"; average maximum wind = 28 mph

FLOWERINGS: Early March: flowers of previous month peaking; desert hyacinth, wild onion flowers common. Late March: peak flowering season for most low-growing plants: globe mallow, desert star, fiddle neck, Gilia, lupine, owl clover, Mexican poppy, verbena, wild onion, desert chicory, etc., etc.. Shrubs like hopbush, Fairy Duster, Mormon Tea and brittle bush bloom. Creosotebush will flower if there is moisture in the soil. (The last half of March is generally the best time to see spring herbaceous flowers.)


FAUNAL ACTIVITIES: Carpenter bees become active, various beetle species appear to feed on blooming plants; Box Turtles emerge and seek mates; Elf Owls arrive from Mexico, breeding at the same time as Burrowing Owls and Barn Owls. Burrowing Owls begin mating. Some migratory songbirds arrive, along with turkey vultures coming from Mexico. A number of birds are tending their new fledglings. Coyotes, foxes, and rock squirrels are bearing their young. Male deer return to their solitary life and begin shedding their antlers.


Image at left: Ocotillo blossoms on hills above the San Pedro River, April 2005.

CLIMATE: Average high temp. = 85 F; average low temp. = 45; average temp. = 65; average rain = .49"; average maximum wind = 34 mph. (Sometimes April becomes quite warm, but it has occasionally snowed during this month.)

FLOWERINGS: Most late March flowers still blooming; early ones likely gone. Hedgehog cacti are early succulent flowers, and Beavertail follows near mid-April, followed by the Opuntias. Late April: mesquite flowers may appear if rain has been favorable; Blue Paloverde bursts out everywhere; Ocotillo blooms are strongest during this time (rainfall depending). The early spring flowers -- poppy, lupine, owl clover, penstemon, mallow, fairy duster, hedgehog cacti et al. conclude their flowering by the end of the month.The Yucca baccata sends up its flower stalks (to be pollinated only by Yucca moths)..


FAUNAL ACTIVITIES: Kissing bugs may appear during this month. Summer hawks -- the Mexican Black and the Zone-tail, also Swainson's Hawk appear and begin the mating process. White-winged Doves return from the south, and Gambel's Quail pair off to mate. Hooded orioles, various migrating flycatchers, and tanagers appear. Sparrows are breeding. Ravens are nesting. Lizards and rattlesnakes become more active. Bobcats, coyotes, and foxes are bearing young. Many kinds of butterflies appear.


Image at left: Saguaro blossoms emerge in May 2002, lower Hot Springs Canyon

CLIMATE: Average high temp. = 95 F; average low temp. = 53; average temp. = 74; average rain = .31"; average maximum wind = 28 mph (May is usually quite hot, and very dry.)

FLOWERINGS: Early May: Mesquite flowers in favorable years, sets pods. Blue Paloverde complete flowering; Foothills Paloverde are in full flower. (Blooming of paloverdes seem to be little influenced by rain conditions.) Night-blooming cacti begin blooming, Saguaros intensify their flowering in late May -- their average peak is May 22. Yucca and Sotol may begin blooming. Coral Beans blossom.


FAUNAL ACTIVITIES: Our exceptional (for the US) variety of Hummingbirds are present in force, meeting the desert flowers and insects. The Kissing Bug is active. White-winged Doves are still arriving from the south, and Gambel Quail chicks are paraded around by their parents. Desert lizards lay their eggs, and Roadrunners feast upon them and build nests. Nectar-feeding bats migrate from Mexico, following the night-blooming flowers. Gila Monster newborns go out on their own, and skunks and badgers are giving birth.


Image at left: tail of retreating Western Diamondback Rattlesnake, Hot Springs Canyon June 2003

CLIMATE: Average high temp. = 104 F; average low temp. = 61; average temp. = 83; average rain = .2"; average maximum wind = 27 mph (Our Junes are generally very hot -- often the hottest maximums occur -- and usually quite dry.)

FLOWERINGS: This driest month of the year marks the end of most herbaceous plants flowering, (datura however blooms at this time), though some woody plants and succulents now flower -- yucca elata, sotol, night-blooming cereus, teddy bear cholla.

RIPENINGS: The leguminous trees are bearing their fruits, Jojoba plants their nuts. Toward the end of the month, the Saguaro fruits ripen -- see this link for more details on this major, historically critical foodstuff for native peoples.

FAUNAL ACTIVITIES: Cicadas sing. many snake species bear live young or lay eggs; hawks are breeding. Lesser Nighthawks are active in the evenings. Mexican ducks may be seen in our ponds, some of them nesting. Many mammals and birds migrate to higher elevations. Deer begin to bear young (continuing through August). Solitary males sprout new antlers.


Image at left: pincushion mammilaria blossoms in Hot Springs Canyon, July 2003

CLIMATE: Average high temp. = 104 F; average low temp. = 68; average temp. = 86; average rain = 2.81"; average maximum wind = 33 mph. (Climatically, this is the month when our Monsoons usually arrive.)

FLOWERINGS: These depend on rainfall, but mammilaria & barrel cacti, jumping cholla, datura, Arizona poppy may bloom.

RIPENINGS: Agaves bloom (which is "ripening" to the native peoples who harvested them -- see this link.) Mesquites and Acacias have ripe bean pods.

FAUNAL ACTIVITIES: Many kinds of insects arrive in migration or hatch out, including the Palo Verde Root-borer Beetle. Leafcutter and Harvester ants swarm to form new nests (see this link). Amphibians (including our Sonoran Desert Toads) emerge with rains and call out for mates. This is a strong month for amphibian and reptile activities -- horned lizards hatch out at this time. Summer sparrows breed. Nectar-feeding bats follow the agave blooms.


Image at left: a pair of Katydids mate in a Palo Verde tree, August 2004.

CLIMATE: Average high temp. = 101 F; average low temp. = 68; average temp. = 85; average rain = 3.38"; average maximum wind = 33 mph. (this is climatically our rainiest month. Plants are at their most lush.)

FLOWERINGS: These depend on rainfall, but barrel cacti, jumping cholla, datura, Arizona poppy may bloom. This is the second blooming period -- sunflowers, Arizona or Summer Poppy, Datura. The vines also come out: trumpet vines, morning glories, Scarlet Creepers. These are accompanied by summer butterflies.

RIPENINGS: Prickly pear cactus ripen, as do the fruits of Desert Hackberry shrubs.

FAUNAL ACTIVITIES: Male Tarantulas are cruising over the lands, looking for females. Regal Horned Toads are hatching. Gila Monsters are finishing their breeding season. Birds (including White-winged Doves) begin to migrate south. Gila Woodpeckers and Flickers drill holes in Saguaro (which they will use when hardened, not now but the following late spring). Red-tailed Hawks become more numerous at this time, as are migrating Western Kingbirds. Kangaroo Rats are active at night.


Image at left: strong August rains leave a deep pond in the Red Tank, September 2001

CLIMATE: Average high temp = 97 F; average low temp = 62; average temp. = 80; average rain = 1.59"; average maximum wind = 26 mph. (In this month, the daily temperatures tend to remain high but nightime temperatures drop significantly, bringing a sense of relief to those now burned-out.)

FLOWERINGS: Few flowers -- mainly sunflowers, snakeweed, fleabane, Hymenoclea, and Desert Broom. Seep-willows also flower in the washes.

RIPENINGS: Prickly Pears are enjoyed by coyotes and others.

FAUNAL ACTIVITIES: If good rains come, the Desert Tortoises move out in force, including the very young. Bats and hummingbirds are both numerous and active, fueling themselves on fruit and insects for winter. fall bird migrations of waterfowl, Western Kingbirds, and many other kinds of birds appear who are just passing through. Turkey Vultures, Zone-tail and Mexican Black Hawks congregate preparing to go south. Deer polish their antler horns, and the young of Javelinas are evident. .


Image at left: one of a rich crop of grasshoppers in lower Hot Springs Canyon, October 2007.

CLIMATE: Average high temp. = 87 F; average low temp. = 50; average temp. = 69; average rain = 1.5"; average maximum wind = 23 mph. (The first cold mornings occur now, though days of heat will follow. Days are noticeably shorter and nights longer.)

FLOWERINGS: Asters, sunflowers, fleabane, Hymenoclea, and Desert Broom continue to bloom. Seep Willows bloom.

RIPENINGS: Many shrubs fruit during this month. Prickly Pear fruits continue to ripen. Deciduous trees drop their leaves. Grasses become more conspicuous as their inflorescences ripen.

FAUNAL ACTIVITIES: Flowering Desert Broom plants draw many butterfly species. Grasshoppers of many species are active. Many snakes go underground. Birds gorge on a variety of insects and fruits.Wintering hawks include Northern Harrier, Ferruginous Hawk, Kestrel, and Prairie Falcon. Cactus Wrens are building their nests for winter. Common Ravens are numerous, sometimes gathering into large and rather noisy conclaves. Packrats are stashing fruits into their messy nests.


Image at left: Fremont Cottonwoods yellow above the Hot Springs Canyon Narrows, Arizona Sycamores brown below, November 2002.

CLIMATE: Average high temp. = 76 F; average low temp. = 33; average temp. = 57; average rain = .82"; average maximum wind = 23 mph. (Historically, the first of November marks the arrival of reliably cool days -- though in recent years, we get some hot ones at this time as well. Freezes occur, more frequently in the valley lowlands. Rain is scanty, except in El Nino years.)

FLOWERINGS: Few flowers -- mainly sunflowers, fleabane, Hymenoclea, and Desert Broom.

RIPENINGS: Leaves of deciduous riparian trees are turning golden colors and falling, and the Arizona Walnut is dropping its fruit. Desert Broom releases clouds of airy white seeds.

FAUNAL ACTIVITIES: Leaf-cutter Ants are very active, as desert trees shed their leaves.Mesquite Buck Moths become common. Phainopeplas return from the north or west, many hummingbirds leave for points south (Anna's however remain). The large desert mammals remain active throughout the winter (and Mule Deer in particular become more frequent), while some small rodents go into hibernation, and Rock Squirrels retreat to their dens. Reptiles are mostly dormant.


Image at left: Skeleton Weed annuals die out to a brittle bright red in Teran Wash, December 2003.

CLIMATE: Average high temp. = 67 F; average low temp. = 33; average temp. = 50; average rain = 1.34"; average maximum wind = 27 mph

FLOWERINGS: Mainly a resting period, with brief periods of freezing, and many trees drop leaves. Rains now are very important for future flowerings. If rains come, Creosotebush, Brittlebush, and Ocotillo stalks will put on bright new leaves at this time.

RIPENINGS: Desert mistletoe, netleaf hackberry tree fruits, are ripe now, and the desert Christmas Cactus fruits turn red.

FAUNAL ACTIVITIES: Anna's Hummingbirds establish mating territories; Cactus Wrens build nests, often in Cholla cacti. Wintering sparrows are active. Phainopeplas gorge on ripe mistletoe berries. Deer begin their rut.