December 2025 Supermoon: When and How to Watch the Year's Final Cold Moon

As 2025 draws to a close, the cosmos has saved one last dazzling performance for skywatchers across the globe. On December 4, 2025, the night sky will be illuminated by the final Supermoon of the year, traditionally known as the "Cold Moon." This celestial event marks the conclusion of a spectacular series of four consecutive Supermoons that began in late summer, offering a breathtaking farewell to the lunar calendar of 2025.

For astronomy enthusiasts and casual stargazers alike, this is an unmissable opportunity to see the moon at its brightest and largest before the new year begins.

What Makes This a "Supermoon"?

The term "Supermoon" isn't just a catchy headline; it describes a specific astronomical phenomenon. A Supermoon occurs when a full moon coincides with the moon's closest approach to Earth in its elliptical orbit, a point known as the perigee.

Because the moon’s orbit around Earth isn't a perfect circle but an oval, its distance from us varies throughout the month. When the moon is at perigee, it can be approximately 363,300 kilometers (225,744 miles) from Earth or even closer.

• Visual Impact: During this time, the moon can appear up to 14% larger and 30% brighter than a micromoon (when the moon is at its farthest point, apogee).

• The Cold Moon: The December full moon is historically called the "Cold Moon" because it rises during the time of year when winter temperatures settle in and the nights become long and dark in the Northern Hemisphere. Other names include the "Long Night Moon" and the "Moon Before Yule."

This specific Supermoon on December 4 is the fourth and final one of 2025, following the Sturgeon Moon in August, the Harvest Moon in September, and the Hunter's Moon in October.

When to Watch: Timing is Everything

To get the best view of the December Supermoon, timing your observation is crucial.

• Peak Illumination: The moon will reach its peak fullness at approximately 6:00 PM EST (Eastern Standard Time) on December 4, 2025.

• Best Viewing Moment: While the moon is technically "full" at a specific minute, the best time to view it is actually at moonrise. As the moon peeks over the horizon, an optical illusion known as the "Moon Illusion" makes it appear significantly larger than when it is high in the sky.

• Duration: The moon will appear full for about three days, from Tuesday evening through Friday morning, giving observers plenty of chances to catch a glimpse if the weather on the peak night is cloudy.

How to Watch: No Equipment Needed

One of the beauties of lunar observation is its accessibility. Unlike comets or distant nebulas that require expensive telescopes, the Supermoon can be enjoyed with the naked eye.

1. Find a Clear Horizon: Look for a spot with an unobstructed view of the eastern horizon for moonrise and the western horizon for moonset. High ground or a beach is ideal.

2. Minimize Light Pollution: While the moon will be bright enough to be seen from cities, escaping to a darker area away from streetlights will enhance the contrast and allow you to see more surface details.

3. Use Binoculars: If you have a pair of binoculars, now is the time to use them. They can reveal the texture of the lunar surface, including its craters and the dark plains known as "maria."

4. Photography Tips: If you plan to capture the moment with a smartphone, try tapping on the moon on your screen to lower the exposure. This prevents the moon from looking like a glowing white blob and reveals its details. Using a tripod is highly recommended for steady, sharp shots.

The Significance of the Cold Moon

Culturally and historically, the December full moon has held great significance. For ancient tribes and early settlers, it signaled the arrival of the harshest part of winter. It was a time to hunker down, preserve resources, and gather around the fire. In modern times, the Cold Moon serves as a celestial nightlight during the longest nights of the year. Its high trajectory across the sky—opposite the low winter sun—means it stays above the horizon for a longer duration than summer moons, casting a brilliant glow over winter landscapes.

A Year of Lunar Wonders

2025 has been a remarkable year for lunar events, and this final Supermoon caps off a season of astronomical beauty. It serves as a reminder of the dynamic and ever-changing nature of our solar system. Whether you are viewing it from a snowy rooftop in New York, a beach in Mumbai, or the quiet countryside of Europe, the Supermoon connects us all under the same sky.

So, mark your calendars for December 4. Bundle up, step outside, and look up to witness the grand finale of the moon's 2025 performance—a silent, glowing giant bidding farewell to the year.