The December 2025 Cold Moon, a supermoon, will be exceptionally large and bright, reaching a high point in the Northern
Hemisphere sky. This celestial event, also known as the Long Nights Moon, occurs when the full moon coincides with
perigee, its closest approach to Earth. Observers can best witness its impressive size and brightness at moonrise on
The December 2025 full moon, widely called the Cold Moon, promises one of the year’s most striking lunar displays. This
supermoon will appear larger and brighter than most other full moons, reaching an unusually high point in the sky for
observers in the Northern Hemisphere. Its proximity to Earth during perigee enhances its size, making it especially
impressive at moonrise shortly after sunset. Historically, this moon is also known as the Long Nights Moon or the Moon
Before Yule, reflecting seasonal traditions. Skywatchers can experience the best views from open, elevated locations
with a clear eastern horizon. The Cold Moon combines natural beauty, celestial science, and seasonal significance,
creating a must-see spectacle for astronomers and casual observers alike.
Understanding the December Cold Moon and its timing
The full moon in December has been traditionally called the Cold Moon because it coincides with some of the chilliest
nights of the year in the Northern Hemisphere. Historically, other names for this moon include the Long Nights Moon and
the Moon Before Yule, referencing the old English term for the winter festival. As reported by Forbes, in 2025, the Cold
Moon will reach full illumination at 8:20 a.m. EST on Thursday, 4 December. Although technically full at this time, the
moon will appear fully visible the night before and the night after. For observers in North America, the most impressive
view is at moonrise, when the moon emerges on the eastern horizon shortly after sunset on Friday, 5 December.
Why the cold moon is a ‘supermoon’
A supermoon occurs when a full moon coincides with the moon’s perigee, the closest point in its elliptical orbit around
Earth. At perigee, the moon appears larger and brighter than usual. For December 2025, the Cold Moon will reach full
illumination just 12 hours after perigee, making it one of the largest and brightest full moons of the year. Its
distance from Earth will be around 221,965 miles (357,218 kilometres), compared with the average lunar distance of
238,900 miles (384,472 kilometres). This places it as the second-closest full moon of 2025, enhancing its size and
brightness in the night sky. A supermoon is only about 10% closer than the average moon, yet this slight difference
significantly impacts its visual prominence, especially when viewed at moonrise near the horizon.
Why December’s cold Moon reaches its highest point in the sky
December’s Cold Moon is not only bright and large but will also appear higher in the sky than any other full moon in the
Northern Hemisphere. This happens because the full moon always rises opposite the sun. With the winter solstice on 21
December, the sun is at its lowest point in the sky. Consequently, the moon mirrors this position, climbing to a height
rarely seen during other full moons. Observing the moon shortly after it rises gives viewers a stunning perspective as
it climbs above the horizon, making the Cold Moon especially dramatic. The early December timing ensures the full moon
appears soon after sunset, creating the perfect conditions for photography and casual stargazing alike.
Best locations and times to view the cold supermoon
To fully appreciate the Cold Supermoon, viewers should seek unobstructed locations with a clear view of the eastern
horizon. Ideal spots include coastlines facing east, elevated fields, or open spaces free from tall buildings and trees.
Sample moonrise times on Friday, 5 December 2025 include:
New York: sunset at 4:29 pm EST, moonrise at 4:56 pm EST
Los Angeles: sunset at 4:43 pm PST, moonrise at 5:27 pm PST
For precise timing in your local area, it is recommended to use a moonrise calculator, which will help ensure you catch
the Cold Moon at its peak visual impact.
Why supermoons appear larger than usual
The phenomenon where the moon looks unusually large near the horizon is called the moon illusion. Although the Cold Moon
is only about 10% closer than a typical full moon, it can appear significantly bigger due to this optical effect.
Objects on the horizon, such as trees, buildings, and mountains, create a visual reference that tricks the human brain
into perceiving the moon as larger. Even though scientists do not have a definitive explanation for the illusion, it
remains a favourite reason for photographers and stargazers to observe the moonrise. The December Cold Moon is the final
full moon of 2025, concluding a year marked by three supermoons and two total lunar eclipses. Previous events included
the March 13-14 and September 7-8 blood moons, making 2025 a notable year for lunar observers. The sequence of
supermoons continues into 2026, with the Wolf Moon on 3 January 2026, which will be the fourth consecutive supermoon.
This event will mark the first full moon of the new year and the first of the Northern Hemisphere winter season. With
its extraordinary size, brightness, and high trajectory across the sky, the December 2025 Cold Moon promises to be an
unforgettable event for both amateur astronomers and casual skywatchers.
Tips to watch the Full Moon December 2025 Cold Supermoon
To get the most out of observing the Cold Supermoon, consider these practical tips:
Choose the right location: Seek an open space with a clear view of the eastern horizon. Elevated fields, coastal areas
facing east, or parks free from tall buildings and trees are ideal for unobstructed moonrise viewing.
Check local moonrise times: While the Cold Moon rises shortly after sunset on Friday, 5 December 2025, the exact timing
varies by location. Use a moonrise calculator to know the precise moment for your area. For example, in New York,
moonrise will be at 4:56 pm EST, while in Los Angeles, it will be 5:27 pm PST.
Time your observation: The best visual impact occurs when the moon first appears above the horizon. This is when the
moon illusion makes it seem largest, enhanced by surrounding trees, buildings, or mountains.
Bring equipment if desired: A camera with a zoom lens or a pair of binoculars can enhance the experience, allowing you
to capture the moon’s size and brightness.
Dress warmly and prepare for night viewing: December nights are cold, so wear appropriate clothing, bring a blanket or
chair, and enjoy the spectacle comfortably.
Following these tips ensures you experience the Cold Supermoon at its brightest, largest, and most dramatic, making it a
memorable astronomical event.