The last full moon of 2024, the Cold Moon, will light up the night sky on Sunday, December 15th. The moon will rise and set on the horizon at its northernmost points, the result of an 18.6-year phenomenon known as a great lunar standstill, according to TimeandDate.com.

What is a severe lunar standstill?

A major lunar standstill occurs when the moon reaches the end points of its orbit around Earth, the Griffith Observatory said in a statement. The moon reaches both a northernmost and southernmost position every 29 days, but from month to month the northern and southern limits of the moon’s rise and set change. “Over an 18.6-year cycle, the Moon’s greatest northern and southern positions extend beyond those of the Sun,” the observatory said. “And just as the sun lingers at its boundaries each solstice, once the moon reaches these extremes, its boundaries do not appear to change.”

While the Sun only stands still for a few days, a major lunar standstill can last two years. During this time, we observe the moon rising and setting at its northernmost and southernmost positions on the horizon, the observatory said.

Why is it called the Cold Moon?

The full moon in December is called the “Cold Moon”. This is “a Mohawk name that expresses the frigid conditions of this time of year when the cold weather really begins to get to us,” says the Old Farmer’s Almanac.

It is also known as the Long Night Moon because it is the full moon closest to the winter solstice, which is the longest night of the year, according to NASA. This year, the winter solstice occurs a few days after the full moon on Saturday, December 21st.

This is how you see the cold full moon

According to NASA, the Cold Moon will appear on Sunday, December 15, passing opposite the Sun at 4:02 a.m. EST. While the moon will officially be full on Sunday, it will also look full on Saturday, December 14th and Monday, December 16th.