What to look for in nature in Arizona this December

When do Arizona’s bald eagles start nesting, and which places close?

• The breeding-area closures

  Usually December 1 to June 30 · Stretches of the Verde and Salt rivers, the Tonto Creek inlet to Roosevelt Lake, and other nest sites

  In its December 2025 bulletin the department counted 111 bald eagle breeding areas statewide and reported that 83 young hatched in the 2025 season, of which 71 lived to make their first flight. To protect the next round, land managers close the ground near certain nests from December 1 to June 30. Last season’s list included the Verde near Chasm Creek, the Verde upstream of the East Verde confluence and near Mule Shoe Bend (float through, but no stopping or landing), the Salt near Meddler Point, and the Tonto Creek inlet to Roosevelt Lake, where land within 1,000 feet of the nest and water within 300 feet were off limits. The Southwestern Bald Eagle Management Committee notes that once eggs are laid, 15 to 30 minutes of disturbance can be enough to end a nesting attempt. The Southwestern Bald Eagle Management Committee’s standing closure list puts most of the Verde, Salt and Tonto Creek areas, Horseshoe Reservoir among them, off limits from December 1 to June 30, with Lake Pleasant following on December 15 and Alamo Lake on January 1. Arizona Game and Fish usually announces the season’s closures around the start of December; check both before any river trip.

• Watching without disturbing

  All winter · Open shorelines and overlooks; the Flagstaff lakes for wintering birds

  Drones and paragliders are asked to keep away from nest areas entirely. On foot, a spotting scope from a legal distance beats creeping closer. Around Flagstaff, look for the wintering birds early and late in the day on snags above open water, and dress for a dawn well below freezing.

Why are phainopeplas and hummingbirds so busy in the desert in December?

• Phainopeplas and desert mistletoe

  Winter, into early spring · Mesquite and palo verde with mistletoe: Saguaro National Park, Sabino Canyon, desert parks around Phoenix

  The phainopepla, a silky-flycatcher, lives largely on the berries of desert mistletoe, a leafy parasite that hangs in tangled clumps from mesquite and palo verde. The Tucson Bird Alliance says a phainopepla eats about 1,100 of the berries in a day and that each berry passes through in roughly 12 minutes; Saguaro National Park explains that the seeds pass through the bird and are left on new host trees, which is how the mistletoe spreads. In winter each bird defends its own clumps hard. The male is glossy black with a ragged crest and white wing patches that flash in flight; the female is plain slate gray. Unusually, they nest twice: in the desert in late winter and spring, then again in oak woodland such as Madera Canyon after the berries run out.

• Anna’s hummingbirds nesting in midwinter

  Nest building can start in December; most nesting from late winter · Neighborhoods, parks and gardens in Phoenix and Tucson

  Audubon’s field guide notes that Anna’s hummingbird may begin nesting in December, earlier than almost any other North American bird, and the Tucson Bird Alliance calls it the most common hummingbird in southeastern Arizona at any time of year, nesting from late winter through summer. In this season, watch for a male climbing high and then diving steeply past a perched female, ending in a sharp pop made by air rushing over his tail feathers. The nest is a tiny cup bound with spider silk, often in a garden shrub; watch it only from a distance.

When are Arizona’s Christmas Bird Counts, and how do I join one?

• Southeastern counts

  Mid-December to early January · Tucson Valley, Santa Catalina Mountains, Avra Valley, Ramsey Canyon, Patagonia, Nogales, Atascosa Highlands, Green Valley–Madera Canyon, Portal, Buenos Aires National Wildlife Refuge and more

  The observatory notes that the Ramsey Canyon count regularly turns in one of the highest inland totals in the country, 150 species or more, because the circle takes in grassland, canyon and the San Pedro’s riverside forest. The Portal count covers the east side of the Chiricahuas, and the Organ Pipe and Ajo–Cabeza Prieta counts reach out into the borderland desert.

• Central and northern counts

  Mid-December to early January · Phoenix, Salt–Verde Rivers, Tres Rios, Gila River, Prescott, Chino Valley, Camp Verde, Jerome, Sedona, Payson, Flagstaff–Mount Elden, Havasu and Bill Williams River refuges

  The Maricopa Bird Alliance says beginners are welcome and that teams are usually matched by identification skill and stamina. Newcomers can keep the tally or watch a feeder inside the circle. The Flagstaff–Mount Elden circle makes for a colder day among the pines, sometimes in snow.

• Cranes at full strength, and a festival in January

  December into February; Wings Over Willcox January 14–17, 2027 · Whitewater Draw near McNeal and fields around Willcox

  By December the sandhill cranes that built up through November are settled for the winter, so the morning liftoff at Whitewater Draw is close to its winter best. The 34th Wings Over Willcox Birding and Nature Festival runs January 14–17, 2027, with registration opening October 10; its tours fill early, so December is the time to book.

Where do Arizona’s tortoises, Gila monsters and bears go in winter?

• Desert tortoises in brumation

  Generally October through March · Rocky slopes and wash banks in the Sonoran Desert

  Arizona Game and Fish’s tortoise adoption guide says desert tortoises normally settle in once nights stay below 50 °F for a few days running, and that breathing, heart rate and metabolism all slow. A tortoise may come out to bask on a warm day and go back in by sundown, which is normal. If you see one in the wild, enjoy it from where you stand and leave it be.

• Gila monsters below ground

  Winter · Burrows in the desert foothills

  Saguaro National Park says Gila monsters spend most of their lives underground anyway, and in winter they may come up only to bask. The park adds a detail few people know: eggs laid in late June hatch in early winter, but the young stay underground, living on their yolk, until spring. So December has new Gila monsters in it, just out of sight.

• Black bears in their dens

  Mostly November through March · The Mogollon Rim, the White Mountains and the Sky Islands

  Arizona Game and Fish says most of the state’s black bears hibernate from November through March, with body temperature, heart rate and metabolism lowered but the bears still somewhat alert. Cubs are usually born in the den in December and January, often twins, small and helpless, and they come out with their mother in April.

How do you tell Arizona’s evergreens and animal tracks apart in winter?

• Ponderosa pine

  All year; bark scent strongest in sun · Flagstaff, the Mogollon Rim, the White Mountains, Prescott, the higher Sky Islands

  The U.S. Fish and Wildlife Service describes the identifying marks: long needles, five to ten inches, in bundles of three, and thick orange bark that comes away in plates like jigsaw pieces. Put your nose to a sunny trunk. Some people smell vanilla, others butterscotch. A fallen cone, three to six inches long, makes a good journal sketch.

• Alligator juniper

  All year · Pinyon-juniper and oak woodland, roughly 4,000 to 6,000 feet: Prescott, Payson, the Sky Islands

  The Forest Service’s fire effects database explains the name: thick bark broken into square scales like an alligator’s back, quite unlike the stringy bark of other junipers. It is the largest juniper of the Southwest and can live about 500 years. The hard, mealy berry-like cones take two years to ripen, so a tree often carries two ages of them at once.

• Reading the signs in the desert

  Best after rain, when washes are damp · Saguaro National Park and any desert trail

  Saguaro National Park’s guide to animal signs is a good December checklist: prickly pear pads with big bites taken out of them (javelina, which travel in groups of two to 30), coyote scat on the trail itself, the long, X-shaped tracks of a roadrunner, quarter-sized tarantula holes rimmed with silk, the earthen mounds of banner-tailed kangaroo rats, and packrat middens of sticks and cholla joints piled under prickly pear.

• A tree for the holidays

  Permits usually sold in November · Coconino, Kaibab and Apache-Sitgreaves national forests

  The national forests sell a limited number of tree-cutting permits through Recreation.gov, first come, first served. The 2026 details were not posted when we wrote; watch the Coconino’s page there.

How much snow does Arizona get in December, and what will El Niño bring?

• The El Niño question

  Through the cool season · Statewide

  Arizona heads into December with the equatorial Pacific running hot, and federal ENSO forecasters (September 10) gave this warm event better than 90 percent odds of reaching the very strong class. A Weather Service study from the Tucson office, which matched decades of rainfall at Tucson International Airport against El Niño years, found that in moderate or strong events the November-to-April season came out above normal 9 times in 11. The same study found December through February alone above normal in only 6 of those 11 winters, and temperatures that tended to run near or a little below normal. In other words, the wet signal is real but spread unevenly through the season, and a dry December would not mean the forecast failed. NOAA’s official December-to-February outlook comes out October 15 and is updated each month; read it at the CPC 90-day outlook page.

• Snow squalls on the interstates

  With any cold front · I-40 and I-17 across the plateau and the Rim

  The Flagstaff Weather Service office warns about snow squalls, brief bursts of heavy snow and wind that can cut visibility to almost nothing within minutes. Check road conditions before driving north.

Will December rain mean desert wildflowers in spring?

• Looking for seedlings

  After a soaking December rain · Open desert flats and bajadas: Picacho Peak, the Tohono O’odham lands west of Tucson, the desert around Phoenix

  The museum says widespread, spectacular shows come only about once a decade, and that rocky, thickly vegetated places like the Tucson Mountains rarely have mass blooms, while Picacho Peak does fairly regularly. Two or three weeks after a good storm, kneel on bare ground between shrubs and look for carpets of tiny paired seed leaves. If the rains keep coming, the payoff is a peak of about two weeks, most often in early to mid-March.

When does the low desert get its first frost?

• Protecting plants on a freeze night

  Clear, calm nights after a cold front · Low spots and open yards in the Phoenix, Tucson and Yuma areas

  A desert freeze is usually brief and comes at dawn after a still, cloudless night, so cover tender citrus, bougainvillea and young cactus in the evening with frost cloth or old sheets that reach the ground, and take the covers off the next morning.

When is the earliest sunset in Arizona, and how short is the solstice day?

What can you see in Arizona’s night sky in December?

• The crescent between Spica and Venus

  Before dawn, December 4 and 5 · Low in the southeast

  A thin waning moon slides past Spica, the brightest star of Virgo, and on toward Venus over these two mornings. Venus is still close to its most brilliant and is climbing away from the sun, heading for its greatest distance from it in early January.

• The Geminids

  Night of Sunday, December 13 into Monday, December 14 · Anywhere dark; the radiant in Gemini is highest around 2 a.m.

  This is usually the year’s richest shower, and this year the timing is kind: the moon is a slim crescent that sets in mid-evening, so the hours after about 9 or 10 p.m. are dark until dawn. The International Meteor Organization gives an ideal rate of about 150 an hour; what you actually see will be fewer, because that number imagines flawless darkness and Gemini straight overhead. Geminids are often bright and slow, and because Gemini is up by mid-evening, children can catch a few before bed.

• Moon and Pleiades

  Evening of Monday, December 21 · East after dark

  At dusk on the solstice, look just beside the waxing gibbous moon for the Pleiades.

• The Cold Moon, the closest full moon of 2026

  Full at 6:28 p.m., Wednesday, December 23 · Rising in the east-northeast around sunset

  The moon reaches full just after it rises, and perigee, its closest point to Earth, follows only about seven hours later, so no full moon of 2026 comes closer, at about 221,700 miles, a supermoon in every sense the term gets used. December 23 is the night to watch; some calendars list the 24th because that is the date in Universal Time.

• The Ursids, and the Quadrantids to come

  Ursids December 22; Quadrantids early January 4, 2027 · North, toward the Little Dipper and the Big Dipper’s handle

  The Ursids are a minor shower of about ten an hour, and this year a nearly full moon swamps them. Save your stamina for the Quadrantids, which peak at about 8:25 p.m. on January 3 by the meteor organization’s prediction, just before a new moon. Their peak is short and the radiant sits low in Arizona’s evening sky at that hour, so try both the late evening of the 3rd and the darkness before dawn on the 4th, and expect modest numbers. Comet Encke, parent of November’s Taurids, begins brightening this month too and should be a binocular target low in the west after sunset by late January and February.

• A star party a few nights after new moon

  Friday, December 11 · Catalina State Park, north of Tucson

  Telescopes from the Tucson Amateur Astronomy Association come to Catalina on December 11, three nights after the new moon on the 8th, according to the state parks calendar; check the park’s page for the start time.

What can families do outdoors in Arizona this December?

Safety notes for December in Arizona