Duration of a full moon: December supermoon still visible

The final supermoon of 2025 occurred in December. Although it has already reached its maximum, it should still look full on Friday, December 5. Those who miss it will have another chance in January 2026.

Timing of December's Full Moon

The December full moon, also recognized as a supermoon, reached its peak at 6:14 p.m. ET on Thursday, December 4, but will continue to appear full on the following night.

The Name of December's Moon

Decembers full moon is traditionally called the Cold Moon. This name, originating from the Mohawk tribe, reflects the chilly conditions typical of the month.

Understanding Supermoons

A supermoon occurs when the moon is closest to Earth in its orbit, making it appear larger and brighter than a standard full moon. Astronomers refer to this phenomenon as a perigean full moon. Supermoons usually happen three to four times a year and often appear in consecutive months.

How Long a Full Moon Lasts

Technically, a full moon is at its peak for only a brief moment. However, to the naked eye, it can seem full for a couple of nights. This means the December 4 full moon will likely still look full on December 5.

December Moon Phases

• Full Moon: Dec. 4
• Last Quarter: Dec. 11
• New Moon: Dec. 20
• First Quarter: Dec. 27

Supermoons in 2025 and Upcoming

2025 featured three consecutive supermoons. The last, the Cold Moon, peaked on December 4. Earlier supermoons occurred on:

• October 6 at 11:48 p.m. Hunters Moon
• November 5 at 8:19 a.m. Beaver Moon
• December 4 at 6:14 p.m. Cold Moon

The next supermoon will be in January 2026, called the Wolf Moon, peaking on Saturday, January 3, at 5:03 a.m. ET.

Winter Solstice 2025

The winter solstice will take place at 10:03 a.m. ET on December 21. It marks the shortest day of the year, with the fewest hours of sunlight, though the difference is less noticeable in southern regions compared to the northern U.S.

Author: Jackson Miller