US News: Skywatchers across the United States have one last celestial treat waiting this week as the Cold Moon, the twelfth and final full moon of 2025, reaches peak illumination on Thursday, December 4. This particular full moon combines two striking features: it qualifies as a supermoon, appearing larger and brighter than average, and it will arc higher across the night sky than any other full moon of the year.
The moon officially turns full at 6:14 p.m. Eastern Time on December 4, but most observers will find the best views come at moonrise on Wednesday evening or Thursday evening, when the low horizon creates the famous “moon illusion” that makes it look enormous. The nearly full orb will remain stunningly bright and round through Friday night as well, giving plenty of opportunities for viewing or photography.
Astronomers classify this as the third in a series of four consecutive supermoons that began in October. A supermoon happens when the full moon coincides closely with perigee, the point in its orbit when the moon is nearest to Earth. The December Cold Moon will be roughly 10 percent larger and noticeably brighter than a typical full moon.
What truly sets this event apart is its altitude. As the Northern Hemisphere approaches the winter solstice on December 21, the sun rides low in the daytime sky. The full moon, always opposite the sun from our perspective, therefore climbs to its highest possible path at night. On December 4 and 5, the moon will soar nearly overhead for observers at mid-northern latitudes, creating long, dramatic shadows and bathing the landscape in unusually intense moonlight.
The name Cold Moon comes from Native American, Colonial American, and European traditions that associate December’s full moon with the onset of deep winter. Other historical names include the Long Night Moon, reflecting its proximity to the year’s longest night, and the Moon Before Yule from Old English sources. Various tribes knew it by equally evocative titles such as the Frost Exploding Trees Moon or the Moon When the Deer Shed Their Antlers.
Clear skies are forecast for much of the country on Wednesday and Thursday evenings, so step outside shortly after sunset, face east, and watch the Cold Moon rise. Even a modest pair of binoculars will reveal crisp craters and dark lunar seas under the bright supermoon glow. For many, this will be the perfect way to close out the astronomical highlights of 2025.
