December 2024 full moon: This weekend's 'cold' moon will feature a lunar rarity

The sky will offer up an early Christmas present this weekend: The year's final full moon, known as the cold moon, will appear early Sunday, Dec. 15.

Though the moon will officially be full Sunday, it will still look plenty full in the night sky both Saturday and Monday as well.

This month's full moon will also feature a lunar rarity: According to TimeandDate.com, the full moon on Dec. 15, 2024, will rise and set at its most extreme northerly points on the horizon — the result of a once-every-18.6 year cycle.

A lunar rarity: The moon reaches its northernmost point on the horizon

The Griffith Observatory in Los Angeles reports that every 18.6 years, our moon reaches the extremes of its orbit around the Earth. "We observe this as the moon rises and sets at its most northerly and southerly positions on the horizon," the Observatory said in a statement.

On December 15, we will observe the Moon rising as far to the north as it ever does, the observatory said. This happens during what's known as the "major lunar standstill."

What is the 'major lunar standstill'

The major lunar standstill results from the rotation of the moon’s inclined orbit over an 18.6-year cycle, the observatory said.

It occurs, Space.com said, because the moon doesn't follow the same path as the sun. "Its rising and setting positions on the horizon change constantly due to the movements of Earth and the moon," Space.com reported.

The Chimney Rock (Colorado) Interpretive Association explains further: "The moon’s orbit of Earth oscillates or wobbles, gradually causing the moon to rise at different points on the horizon over the years. The entire cycle of wobbling north to south and north again takes 18.6 years.

"At each end of its swing, the moon appears to pause for about three years, rising at the same point on the horizon before beginning to move back toward the opposite end of the swing. This pause is known as a major lunar standstill."

When is the full moon?

December's full moon will reach peak illumination on Sunday, Dec. 15 at 4:02 a.m. EST, according to the Old Farmer’s Almanac.

Why is it called the cold moon?

December’s full moon is most commonly known as the cold moon, which is "a Mohawk name that conveys the frigid conditions of this time of year when cold weather truly begins to grip us," the Old Farmer's Almanac said.

NASA agrees, adding that "the cold moon gets its name because December is the month when it really starts to get cold, although our coldest average temperatures are in January."

It's also called the 'long night moon'

Another name for the December moon is the long night moon, due to its proximity to the winter solstice, which marks the longest night of the year.

The winter solstice this year is Saturday December 21 at 4:19 a.m. EST.

When is the first full moon of 2025?

January’s full moon, the first of 2025, will rise on Monday, Jan. 13. It’s dubbed the wolf moon, since wolves’ howls were more likely to be heard during winter, per the Almanac.

Contributing: Cailey Gleeson, The Milwaukee Journal Sentinel; Iris Seaton, The Asheville Citizen Times

This article originally appeared on USA TODAY: December 2024 full moon is coming soon and brings a lunar rarity