Full Moon December 2025: Final supermoon of the year to be visible December 4; know when, where and how to watch

The December 2025 Cold Moon, a supermoon, will be exceptionally large and bright, reaching a high point in the Northern Hemisphere sky. This celestial event, also known as the Long Nights Moon, occurs when the full moon coincides with perigee, its closest approach to Earth. Observers can best witness its impressive size and brightness at moonrise on December 5th.