Every December, skywatchers gather under crisp winter skies to witness one of the year’s most evocatively named full moons: the Cold Moon. But this year, the event comes with a cosmic twist — a rare Cold Moon Supermoon, a dazzling lunar show caused when the Moon reaches its full phase near perigee, the closest point to Earth in its orbit. And among all 50 U.S. states, Arizona stands out as the No. 2 best location to witness the spectacle, thanks to its exceptional atmospheric conditions, wide-open desert vistas, and extremely low cloud cover during late December.
The ranking reflects not just happenstance, but a convergence of geography, climate, and astronomy that makes Arizona one of the premier lunar-viewing destinations in North America. From the high deserts of Flagstaff to the saguaro-studded valleys of Tucson and the dark-sky preserves around Sedona, Arizona offers some of the clearest, darkest, and most unobstructed views of the night sky anywhere in the United States.
This year’s Cold Moon Supermoon promises to be especially bright, especially large, and unusually photogenic — and Arizona sits nearly at the epicenter of prime viewing conditions.
Why December’s Moon Is Called the “Cold Moon”
The name “Cold Moon” originates from traditional Native American and early Colonial naming systems for full moons, which assigned each month’s moon a name reflecting seasonal changes. For tribes across the northern U.S., December marked:
The arrival of deeper winter cold
Longest nights of the year
Seasonal dormancy in plants
Migration and hibernation cycles in local wildlife
The Cold Moon isn’t just a poetic term — it’s an astronomical milestone as it typically aligns with the winter solstice season, when Earth’s axial tilt causes the Northern Hemisphere to experience its longest and darkest nights.
This extended darkness enhances the Moon’s brightness, making December’s full moon feel particularly luminous.
What Makes This One a Supermoon?
A supermoon occurs when the full moon coincides with perigee, the Moon’s closest point to Earth in its elliptical orbit. When this happens, the Moon can appear:
Up to 14% larger
Up to 30% brighter
Noticeably more detailed, with enhanced contrast visible to the naked eye
For photographers, a supermoon means crisp shadows in craters, sharply defined maria (the “seas”), and a glowing lunar disc that dominates the sky.
Supermoons typically occur several times per year, but a December Cold Moon Supermoon is comparatively rare because the Moon’s perigee cycle is not synchronized with the calendar year. The next time the Cold Moon aligns so closely with perigee won’t occur for several years.
Why Arizona Ranks No. 2: A Perfect Storm of Sky Conditions
Arizona’s exceptionally high ranking comes from a combination of factors that professionals in atmospheric sciences and astronomy have studied extensively:
1. Extremely Low Cloud Cover in December
December is one of Arizona’s clearest months. Statewide climate data shows:
Large parts of the state average over 80% cloud-free nights
Desert regions experience low humidity, minimizing haze
Cold, dry air reduces atmospheric scattering, enhancing contrast
While many northern states grapple with snowstorms and Pacific-coast states face seasonal cloud belts, Arizona remains remarkably clear.
2. High Elevation = Thinner Atmosphere
Cities like Flagstaff, Sedona, and Prescott sit thousands of feet above sea level. Higher elevation means:
Less atmospheric distortion
Reduced light scattering
Sharper, more stable lunar viewing
Flagstaff, home of the Lowell Observatory, is internationally recognized as a premier high-altitude astronomy hub for this very reason.
3. Dark-Sky Protections
Arizona is a global leader in dark-sky conservation:
Flagstaff was the world’s first International Dark Sky City
Sedona, Fountain Hills, and communities across the state enforce strict light pollution controls
Vast wilderness areas ensure natural darkness
In many states, suburban sprawl ruins night-sky clarity. Arizona, uniquely, has embraced astronomy as part of its identity.
4. Wide Open Horizons
Thanks to its desert landscapes, Arizona offers unobstructed 360-degree views. This matters for moonrise and moonset, when the Moon:
Appears largest due to the moon illusion
Takes on deeper oranges and reds
Aligns beautifully with desert silhouettes
There are few places better to witness the supermoon rising over saguaro cactus stands or sandstone formations.
5. Ideal Timing with Local Weather
Meteorologists note that late December in Arizona often brings:
Stable air masses
Minimal atmospheric turbulence
Crisp visibility spanning dozens of miles
All together, these conditions create a natural “observatory” spanning the entire state.
The Only State Ranking Higher: Who Beat Arizona?
The top-ranked state (No. 1) edged out Arizona due to slightly lower cloud-cover probabilities and extremely high-altitude viewing regions — typically states like New Mexico or Nevada, both known for dry desert air and strong dark-sky protection.
Still, Arizona’s mix of elevation, darkness, and open desert places it firmly in the top tier.
Best Places in Arizona to Watch the Cold Moon Supermoon
1. Sedona
Famous for red rock silhouettes
Some of the darkest protected skies in the state
Incredible moonrise opportunities between rock formations
2. Lowell Observatory – Flagstaff
Professional-grade equipment made available to the public
Crisp high-altitude air for peak lunar clarity
3. Tucson & Saguaro National Park
Iconic saguaro cacti provide dramatic foregrounds
Warm desert nights compared to northern Arizona
4. Grand Canyon National Park
Immense horizons
Stunning lunar illumination across canyon layers
Some of the least polluted skies in the continental U.S.
5. Monument Valley
Technically on the Arizona–Utah border, but an unbeatable scenic environment with towering buttes that frame lunar photography beautifully.
6. Kitt Peak National Observatory
High-elevation viewing
Minimal light pollution
Clear atmospheric windows
7. Lake Havasu & Western Arizona
For those who prefer warmer night temperatures, western Arizona offers mild winter weather and big-sky conditions.
How the Cold Moon Will Look in Arizona
Arizona’s atmospheric clarity causes the supermoon to appear:
Extra sharp, revealing high-contrast crater rims
Bright enough to cast shadows
Golden-orange at moonrise, then icy silver at zenith
Large against desert mountains, mesas, and cactus silhouettes
Many photographers describe Arizona supermoons as looking “closer” and “more three-dimensional” compared to humid or cloudy regions.
Ideal Viewing Tips
1. Watch the Moonrise
The most dramatic moment. The horizon magnifies the Moon visually and adds color.
2. Avoid City Centers
Even in dark-sky states, streetlights reduce contrast. Aim for outskirts or designated dark-sky areas.
3. Use Binoculars or a Small Telescope
Even a beginner’s pair of binoculars reveals:
Tycho’s long crater rays
Mare lavender-gray textures
Highland bright patches
4. Bring a Tripod if Photographing
The supermoon is bright, but long exposures create stunning landscape–moon composites.
5. Stay Warm
Even desert nights can dip near freezing in December.
How Rare Is a Cold Moon Supermoon?
On average:
A Cold Moon aligns with perigee only every 8–10 years
A supermoon as bright as this one occurs even less frequently
The next one of similar magnitude may not occur for years
Arizona’s prime conditions make this rare event even more special.
Cultural and Scientific Significance
Across civilizations, the Cold Moon has marked:
The end of seasonal cycles
A symbolic “reflection period” before the new year
A time for winter storytelling and celestial observation
Astronomically, December full moons help scientists:
Study lunar reflectivity
Calibrate telescope sensors
Analyze atmospheric transparency in testing sites
Arizona’s observatories often use supermoon nights to capture calibration data thanks to the consistent brightness.
Arizona’s Astronomy Legacy Makes the Event Even More Meaningful
Arizona is not just a great viewing state — it is one of the world’s astronomy capitals.
The Lowell Observatory discovered Pluto.
The Kitt Peak Observatory houses one of the planet’s largest collections of optical telescopes.
The state has more dark-sky communities than nearly any other region on Earth.
The Cold Moon Supermoon aligns with this legacy, offering a celestial finale to the year.
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