Look up! Colorado skywatchers are in for a striking sight. On December 4, 2025, the Cold Moon Supermoon will rise over the state’s mountains, foothills, canyons, and plains — and Colorado has been ranked the #3 state in the nation for seeing it clearly. This Cold Moon is also the final supermoon of 2025, completing a rare three-supermoon sequence to close out the year.
Photo: Denver Astronomical Society
According to the Supermoon Visibility Index from Action Network — which analyzed sky clarity, humidity, elevation, and darkness across all 50 states — Colorado places near the top in its likelihood of delivering an unobstructed, haze-free view.
The Story Behind the Cold Moon
December’s full Moon is traditionally known as the Cold Moon, signaling the deep arrival of winter and the longest nights of the year. Many cultures also call it the Long Night Moon, tied to stillness, frost, and early sunsets.
Why This One Is a Supermoon
This year, the Cold Moon reaches peak fullness when the Moon is near one of its closest points to Earth — making it a supermoon. It will appear slightly larger and brighter, especially low on the horizon at moonrise.
It also follows November’s unusually small new Moon, creating a dramatic visual contrast.
And this Cold Moon will be one of the highest-rising full Moons in northern skies until 2042, increasing its brightness and visibility.
Why Colorado Ranks #3
Colorado brings together nearly ideal conditions for a crisp, dramatic supermoon including the following:
The highest average elevation in the United States
Thin, dry mountain air that reduces distortion
Strong winter clarity and frequent crisp December evenings
Large stretches of wilderness far from urban glow
Together, these factors give Colorado some of the best viewing odds in America — and produce moonrises that are brighter, sharper, and more visually striking than those at lower elevations.
Best Places in Colorado to Watch the Cold Moon
Rocky Mountain National Park — moonrise over jagged peaks
Garden of the Gods — glowing Moon framed by sandstone towers
Great Sand Dunes National Park — bright dunes under dark skies
Boulder’s Flatirons — iconic skyline foreground
Eastern Plains — enormous, unobstructed horizons
When & How to Watch
The peak illumination will be at 5:14 p.m. MST on December 4, 2025.
The best viewing is around moonrise, when the moon appears largest and most colorful. Choose an open horizon, away from city lights. Be sure to steady your camera on a tripod or railing.
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