December full moon 2025: See the Cold supermoon
It's the last full Moon of the year, and it's not just any full Moon, it's a supermoon. The third of three consecutive supermoons to round out the year, so if you missed November and October's, make sure you head out for this one. Supermoons are what the name suggests, a full Moon that appears bigger and brighter in the sky than usual, perfect for late-night stargazing.
There's lots to know about this Moon, so keep reading to find out when it is, and what it means.
When is the December Full Moon?
December's full Moon will occur on Thursday, Dec. 4. Time and Date estimates it will peak at 6:14 p.m. ET.
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What is the December full Moon called?
Full Moons all have their own names, and December's is traditionally known as the 'Cold Moon'. As you might imagine, this name has something to do with the arrival of winter, and the drop in the temperature.
December's Full Moon is also a supermoon, which means it appears larger and brighter than usual because it’s closer to Earth in its orbit. This happens when the Full Moon occurs near its closest point to our planet, called lunar perigee, giving us a fuller, more prominent view in the night sky, Royal Museums Greenwich tells us.
When is the next Full Moon?
The next Full Moon is predicted to occur on Jan. 3, 2026.
What are the lunar phases?
The Full Moon is just one phase in the Moon’s 29.5-day orbit around Earth. The different phases show how much of its surface is lit up from our point of view. We always see the same side of the Moon, but as it circles Earth, the sunlight falls on it differently. That’s why sometimes it appears full, sometimes half, and at other times seems to disappear entirely.
There are eight main Moon phases, and they follow a repeating cycle:
New Moon — The moon is between Earth and the sun, so the side we see is dark (in other words, it's invisible to the eye).
Waxing Crescent — A small sliver of light appears on the right side (Northern Hemisphere).
First Quarter — Half of the moon is lit on the right side. It looks like a half-moon.
Waxing Gibbous — More than half is lit up, but it’s not quite full yet.
Full Moon — The whole face of the moon is illuminated and fully visible.
Waning Gibbous — The moon starts losing light on the right side.
Last Quarter (or Third Quarter) — Another half-moon, but now the left side is lit.
Waning Crescent — A thin sliver of light remains on the left side before going dark again.
Lois Mackenzie is a freelance reporter at Mashable. Over the years she has written for many publications, covering everything from the local news to the best pair of running shoes. You can find bylines in publications including Fit&Well, Metro, and Coach magazine, usually covering deals on everything from earbuds to TVs, or guides on how to beat your half marathon time.
Lois also holds a Master's degree in Digital Journalism from Strathclyde University and obtained a Master of Arts in English Literature at the University of Aberdeen.
