The December full moon, called the cold moon, will peak on Thursday, Dec. 4 at 6:14 p.m. ET and is the third and final supermoon of 2025. A supermoon occurs when the Moon is near perigee and can appear up to about 14% larger and 30% brighter, according to NASA. Key moon phases around this event include first quarter on Nov. 28 and new moon on Dec. 20 (Moon Giant). Check local moonrise times and weather for the best viewing.
Cold Moon Peaks Dec. 4 — Catch the Final Supermoon of 2025
The December full moon, called the cold moon, will peak on Thursday, Dec. 4 at 6:14 p.m. ET and is the third and final supermoon of 2025. A supermoon occurs when the Moon is near perigee and can appear up to about 14% larger and 30% brighter, according to NASA. Key moon phases around this event include first quarter on Nov. 28 and new moon on Dec. 20 (Moon Giant). Check local moonrise times and weather for the best viewing.
01:24 PM, 11/19/2025Science
The December full moon, commonly called the cold moon, will reach peak illumination on Thursday, Dec. 4 at 6:14 p.m. ET, according to Space.com. This will be the third and final supermoon of 2025, following supermoons in October and November.
Why it’s a supermoon
A "supermoon" occurs when the Moon's elliptical orbit brings it unusually close to Earth at perigee. At that nearer distance a full Moon can appear noticeably larger and brighter—up to about 14% larger in diameter and as much as 30% brighter than an average full moon, per NASA.
Best time to watch
The Moon will appear fullest at the peak moment on Dec. 4 at 6:14 p.m. ET, but it will look full throughout the night and for a day or two on either side of that moment. For dramatic size and color, view the Moon close to the horizon just after moonrise or before moonset—at that angle atmospheric scattering can produce warm, orange tones and a stronger apparent size (the Moon illusion).
Moon phases around the event
Per Moon Giant, the relevant phases are:
First quarter: Nov. 28
Full moon: Dec. 4
Last quarter: Dec. 11
New moon: Dec. 20
Where the name comes from
The name cold moon traces to a Mohawk term reflecting the season’s chill. Many traditional full-moon names recorded by sources such as The Old Farmer's Almanac come from Native American observations of seasonal changes.
Viewing tips
For the best experience: check the forecast and local moonrise times for your location, find a spot with a clear horizon, and bring binoculars or a modest telescope for surface detail. Use a tripod and a telephoto lens if photographing—exposure settings differ if you include foreground elements versus a close-up moon shot.
Looking ahead
The next full moon after December will be the wolf moon, peaking on Saturday, Jan. 3, 2026; it is also expected to be a supermoon. For exact timing and visibility in your area, consult resources such as Space.com, NASA, and Moon Giant.