The last supermoon of the year arrives this week, closing out 2025 with one more bright sky event. The skies will
witness the December full moon - widely known as the Cold Moon - and Thursday will be the final chance to catch a
supermoon before the calendar turns.
What the Cold Moon refers to
The name ‘Cold Moon’ has long been tied to the December full moon, a reference to the sharp drop in temperatures this
time of year. The Almanac lists it as one of the traditional monthly full-moon names, each carrying some seasonal or
cultural cue. December’s label is literal: the cold lands first, then the moon.
Why this full moon qualifies as a supermoon
This week’s full moon is also a supermoon. According to NASA, a supermoon occurs when the moon reaches a point in its
orbit where it swings closest to Earth, known as perigee. When that happens at the same time as a full moon, the lunar
disc looks slightly bigger, slightly brighter. The difference is enough that it stands out to the naked eye.
At the closest approach, NASA notes, a supermoon can appear around 14% larger and 30% brighter than the faintest full
moon of the year. There are usually three or four such events annually. This one is the third in a row, following
December Supermoon 2025: Peak timing and visibility tips
Peak illumination for the December supermoon is expected on Thursday, 4 December, at 6:14 pm ET, according to the
Almanac. It will be visible all evening, but the period just after moonrise usually gives viewers the clearest sense of
A telescope or binoculars will add surface detail, though they are not necessary. Visibility depends more on conditions
on the ground, such as low light pollution, an open line of sight, and steady weather. Flat fields, rooftops, or any
spot without heavy glare from buildings tend to work well, according to Time magazine.
There are no unusual sky events tied to this supermoon. It is simply the last one of the year. For anyone tracking
2025’s lunar cycle, this Cold Moon closes out a three-month run of consecutive supermoons and wraps up the final full
What is the Super Cold Moon?
It’s the December full moon, named for the cold season and marking the last supermoon of the year.
Why is December’s full moon considered a supermoon?
It is the time when the moon reaches perigee, appearing slightly larger and brighter than an average full moon.
When will the December supermoon peak?
The December supermoon peak reaches peak brightness on Thursday, 4 December, at 6:14 pm ET, according to the Almanac.
How can I get the best view of the Super Cold Moon?
To observe the Super Cold Moon, select a location with minimal light pollution and an open, dark area; binoculars can
help reveal surface details.