Supermoon to reach its peak in California's sky. What you need to know about December's full moon

The night sky over California is about to host a spectacular lunar event. The final full moon of 2025 will also be a supermoon, appearing unusually large and bright to observers across the state. This marks the third consecutive supermoon visible in California, following the harvest moon on October 6 and the beaver moon on November 5, creating a rare sequence for sky enthusiasts.

When to Watch the December Supermoon in California

The 12th full moon of the year will reach its peak at 3:14 p.m. on Thursday, December 4, according to Time and Date. Observers can enjoy the moon in the evening sky as it rises after sunset.

Understanding a Supermoon

A supermoon occurs when a full moon coincides with its closest approach to Earth, known as perigee. At this point, the moon appears up to 14% larger and 30% brighter than when it is at its farthest distance, called apogee. During perigee, the moon is roughly 356,000 kilometers from Earth, compared to about 406,000 kilometers at apogee.

The Name Cold Moon

Decembers full moon is traditionally called the Cold Moon, a name dating back to the Mohawk people that reflects the dropping temperatures at the end of the year. In the U.S., it has also been referred to as the Long Night Moon, Drift Clearing Moon, Snow Moon, Frost Exploding Trees Moon, and Hoar Frost Moon. In Europe, pagans called it the Moon Before Yule in reference to the winter solstice festival celebrating the return of longer days.

Supermoon Streak in 2025

This December supermoon is the third of three supermoons in 2025. California ranks among the top ten states for observing this event, placing sixth on the Supermoon Visibility Index, which considers sky clarity, humidity, elevation, and darkness.

Potential Effects on Nature

The extra-large moon may contribute to slightly higher tides along Californias coast, sometimes called king tides, although the effect is generally modest.

Best Ways to Observe and Photograph

The supermoon is most visible near the eastern horizon just after sunset, around 4:45 p.m. It may appear even larger due to the moon illusion, a visual phenomenon making objects near the horizon seem bigger. Photographers are encouraged to frame the moon with natural or urban landscapes. NASA advises using phones with flash off, focusing on the moon, and stabilizing cameras with a tripod.

Upcoming Supermoon in California

Residents wont have to wait long for the next supermoon. The wolf full moon on Saturday, January 3, 2026, will also be a supermoon, continuing the streak of consecutive large lunar displays above the United States.

Author: Harper Simmons