December’s full Cold Moonrises on Saturday, December 18, 2021! And it’s a “Micromoon.” Learn more about what the Cold Moon and what makes it special.
When to See December’s Full Moon
December’s Cold Moon reaches peak illumination on Saturday, December 18, 2021, at 11:37 P.M.EST.
Start looking for the full Moon just before sunset as it begins to peek above the horizon. To find the exact time that it will appear in your area, consult our Moonrise Calculator.
What makes December’s Full Moon special?
First, it’s most distinctive for its high trajectory across the sky, which results in the full Moon sitting above the horizon for a longer period of time.
Second, it’s a “Micromoon” this year. Think of this term as the opposite of a “Supermoon.” It simply means that the full Moon is at its farthest point from Earth (not the nearest point). In astronomical terms, we call this its “apogee.” Specifically, December’s Micro Full Moon is about 252,000 miles from Earth.
Why is the Moon nearer or farther (in this instance) from Earth? Simple: The Moon orbits Earth in an elliptical path. One side is nearer to Earth and one side is farther. This distance does affect the Moon’s size and brightness, although it’s probably not that visible to the naked eye. The perceived size of the Moon from Earth is more related to the “Moon Illusion” and how close the Moon appears to the horizon; in this case, it’s high above the horizon so it may not appear to loom over us the way it appears when it’s near the horizon.
Look up at the full Moon on the 18th (or a day earlier or later)! What do you think?
Why Is It Called the Cold Moon?
The Moon names we use in The Old Farmer’s Almanac come from Native American, Colonial American, or other traditional sources passed down through generations. A variety of Native American peoples traditionally used the monthly Moons and nature’s corresponding signs as a calendar to track the seasons.
Today, December’s full Moon is most commonly known as the Cold Moon—a Mohawk name that conveys the frigid conditions of this time of year, when cold weather truly begins to grip us.
Alternative December Moon Names
Other names that allude to the cold and snow include Drift Clearing Moon (Cree), Frost Exploding Trees Moon (Cree), Moon of the Popping Trees (Oglala), Hoar Frost Moon (Cree), Snow Moon (Haida, Cherokee), and Winter Maker Moon (Western Abenaki).
This full Moon has also been called the Long Night Moon (Mohican), as it rises during the “longest” nights of the year, which are near the December winter solstice. This name is doubly fitting because December’s full Moon shines above the horizon for a longer period of time than most full Moons.
Other names include Moon When the Deer Shed Their Antlers (Dakota) and Little Spirit Moon (Anishinaabe).
In Europe, ancient pagans called the December full Moon the “Moon Before Yule,” in honor of the Yuletide festival celebrating the return of the sun heralded by winter solstice.