December 2025 cold supermoon: Tonight’s full moon will be a spectacular sky-watching finale. Here’s how to see it
Endings are tricky: You want closure and to go out with a bang—which is a hard balance. It’s natural to want the end of the year to be meaningful. Even the moon appears to agree with this sentiment, and it’s about to prove it.
The final full moon of 2025, which is also called the cold moon, will be a bright supermoon occurring on December 4.
Before we get into how best to moon-gaze, let’s break down what that all means, and do a year-end moon review.
Why is December’s full moon called the ‘cold moon’?
Human beings assign names even to celestial happenings. The Old Farmer’s Almanac compiled the most commonly used monikers, based on Old English and Native American sources.
December’s moon is called the cold moon because of the chilly winter temperatures. According to EarthSky, it is also known as Moon Before Yule or the Long Night Moon.
What is a supermoon?
The moon orbits Earth in an elliptical pattern, which means the orb has differing proximity to the planet.
When the full moon lines up with the closer approach to Earth, known as perigee, a supermoon occurs. The moon appears brighter and fuller because it is physically closer to Earth.
What makes this supermoon special?
December’s supermoon offering is the finale of three consecutive supermoons, which also occurred in October and November this year.
Because the orb will mirror the sun, December’s supermoon will also be the highest-hanging full moon of 2025.
What is the moon’s 2025 recap?
There were 12 full moons in 2025. (Sometimes, because of the lunar year length, there are 13, such as in 2023.)
2025’s dozen included three supermoons, two total lunar eclipses—and a partridge in a pear tree. (Well, the scientific nature of the latter is questionable . . . but ’tis the season.)
How best to view the December supermoon
The most dramatic time to view the supermoon is just after moonrise, because of the “moon illusion.”
This phenomenon, which is when the moon appears larger when near the horizon, can’t be fully explained by science. This optical illusion of sorts, combined with the fact that the supermoon appears brighter and bigger, makes for one spectacular nighttime view.
Since viewing times vary by location, use this moonrise tool to best plan your moon-gazing experience.
If you miss tonight, never fear. The moon will reach its peak on December 4 at 6:14 p.m. ET, but it will appear full for a couple of days, so you have wiggle room that allows for more moon-gazing opportunities.
