It is called the Cold Moon because it is the traditional name for December’s full moon, a time associated with the onset of winter and the coldest, longest nights of the year in the Northern Hemisphere.

Seasonal reason

December’s full moon gained the name “Cold Moon” because it appears when temperatures drop sharply and winter conditions set in, so the name simply reflects the harsh cold typical of this part of the year. The name highlights that this full moon usually occurs near the winter solstice, when nights are long, dark, and often freezing.

Cultural origins

The “Cold Moon” label in widespread modern use is linked to Native North American naming traditions that tied each full moon to seasonal changes, with December’s moon marking bitter cold and difficult winter living conditions. Specific attributions vary, but sources often connect the term to Indigenous groups such as the Mohawk, and note that related names like “Long Night Moon” were used by others such as the Mohican.

Other traditional names

December’s full moon is also known by several alternative names that describe the same time of year. Common variants include:

• Long Night Moon, emphasizing the very long winter nights.

• Moon Before Yule or Oak Moon in some European traditions, referring to its proximity to midwinter and Yule festivals.