Cold Moon: December's full moon

Where the name Cold Moon comes from

The meaning of December’s popular name needs no explanation. The attribution is more specific than usual. The Old Farmer’s Almanac (New Hampshire) says Cold Moon was a name used by the Mohawk, for the time when winter cold takes hold. The Farmers’ Almanac, a separate publication based in Maine, explains it as the full moon near the start of winter.

As with the other popular names, the almanac’s attribution has not been independently confirmed, and “Cold Moon” is not part of a single Native American calendar. That calendar never existed. The twelve-name list was assembled by almanacs from Indigenous, colonial and European sources and matched to Gregorian months. Indigenous names varied by nation and dialect, and many named a whole lunar month. The almanac also lists Cold Moon as a Cree name for January, a reminder that the same English phrase turns up in different months. Our full moon names overview has more on how the list formed.

Other names for December’s full moon

The Old Farmer’s Almanac credits these names to specific nations. We report its attributions as given.

• Long Night Moon: Mohican.
• Mid-Winter Moon: Lakota and Northern Ojibwe.
• Moon of the Popping Trees: Oglala.
• Drift Clearing Moon, Frost Exploding Trees Moon and Hoar Frost Moon: Cree.
• Snow Moon: Haida and Cherokee.
• Winter Maker Moon: Western Abenaki.
• Moon When the Deer Shed Their Antlers: Dakota.
• Little Spirit Moon: Anishinaabe.

Indian Country Today (ICT), a Native-run news outlet, gives the Ojibwe name Mannidoo-giizisoons, the Little Spirit Moon. In the almanac’s list, January’s Ojibwe name is Spirit Moon, and ICT’s is the Great Spirit Moon, so the two months form a pair. The Farmers’ Almanac uses Long Nights Moon without attributing it to any nation.

ICT’s Dakota list gives Čhaŋkáphopa wí, the Popping (or Exploding) Trees Moon. The almanac credits a similar name to the Oglala. The Oneida name translates as “It’s a Long Night,” and the 1890s Cherokee seminary calendar gives Frosty Moon.

There is also a seasonal almanac name. Moon Before Yule was the old Maine Farmers’ Almanac’s name for the last full moon before the winter solstice, which the almanac called Yule. Sky & Telescope’s history of the Blue Moon shows why it matters: the old Maine Farmers’ Almanac called the third full moon of a four-moon season “blue,” so that names like Moon Before Yule would still land on the right moon.

What makes the Cold Moon notable

December’s full moon is usually the year’s highest-riding and longest-lasting full moon for the United States. NASA explains that a full moon is on the opposite side of Earth from the Sun. Near the December solstice the Sun takes its lowest, shortest path, so the full moon takes the highest, longest one. It rises in the northeast around sunset, passes high in the south around midnight and sets in the northwest near sunrise. It shines for almost the whole of the year’s longest nights, which is where Long Night Moon fits.

The flip side is that December’s full moon brightens the sky for many hours. When it is near mid-month, it interferes with the Geminid meteor shower. When it is late in the month, it overlaps the minor Ursid shower around the solstice.

How to watch the Cold Moon

The table above shows moonrise for major cities on the best evening. Because December sunsets are early, you can see it rise at the end of the afternoon. Look northeast, which is farther north than many people expect.

The rising Moon will look very large. NASA describes the Moon illusion as a matter of perception, not optics. A camera records the same width at the horizon as high in the sky, and the explanation is still debated. The amber color near the horizon is real. It comes from moonlight crossing the thick lower atmosphere.

Later in the night, the high Cold Moon is a good target for binoculars. Even a small pair steadied on a fence post shows the dark lava plains clearly. Dress warmly. Our city sky pages list the darker nights later in the month for stars and planets.