The December 2025 full moon is not only beautiful, it's also uncommon. Here's why

The final full moon of December is set to appear this week, promising a striking spectacle in the night sky. Known as the Cold Moon, it will reach full illumination on Thursday, December 4, 2025, at 6:14 p.m., as reported by the Old Farmer's Almanac.

This December full moon marks not only the last full moon of 2025 but also concludes a series of supermoons that have wowed skywatchers over the past three months. The first full moon of January 2026 will also be a supermoon.

Understanding the Supermoon Effect

While there is no strict scientific definition for a supermoon, these moons appear roughly 14% larger and 30% brighter than an average full moon, according to the Natural History Museum. This phenomenon occurs because the moons orbit around Earth is elliptical. When the moon is at its farthest point, called apogee, it produces a smaller micromoon. At its closest approach, or perigee, it creates the bright and enlarged supermoon.

The Meaning Behind the Cold Moon

The December full moon earned the name Cold Moon because it reflects the onset of harsh winter conditions. The Old Farmer's Almanac notes that it is a Mohawk term for the frigid season and has also been called the Long Night Moon by the Mohican, as it rises during the years longest nights, around the winter solstice.

Other Names for the December Full Moon

• Moon When the Deer Shed Their Antlers (Dakota)

Best Ways to Observe the Cold Moon

No special instruments are required to enjoy this full moon, but stargazing experts recommend using a telescope or binoculars for a more detailed view. According to Tim Brothers, a technical instructor and observatory manager at MIT, these tools significantly enhance the experience.

Looking Ahead

The first full moon of 2026, known as the Wolf Moon, will appear on January 3, 2026, reaching its peak at 5:03 a.m., continuing the cycle of spectacular lunar displays.

Author: Sophia Brooks