2025 is ending with a rare run of three back-to-back supermoons because the timing of the Moon’s closest approach to Earth has lined up unusually neatly with three consecutive full moons.
This orbital coincidence makes the full moons of October, November and early December all qualify as “supermoons”, with the next one due on December 5 also known as the Cold Moon.
WHAT MAKES A SUPERMOON
A supermoon happens when a full moon occurs near perigee, the point where the Moon is closest to Earth in its slightly elliptical orbit.
At perigee, the Moon can appear up to about 14% larger and around 30% brighter than a full moon at its farthest point, called apogee, though the size difference is subtle to the naked eye.
Astronomers call this alignment of Sun, Earth and Moon at full phase “perigee syzygy”, which is the technical basis for what popular culture labels a supermoon.
WHY THREE SUPERMOONS IN A ROW
The key to 2025’s triple supermoon lies in how the timing of perigee slowly shifts relative to the lunar phases over time. Perigee cycles through the phases roughly every 14 lunar months, so in some years only one full moon is close enough to perigee to be classed as “super”, while in others, several full moons fall within that threshold.
In late 2025, that cycle happens to place perigee within a narrow time window of the full moons in October, November and early December, producing three consecutive supermoons, with an additional one following in early January 2026.
THE DECEMBER SUPERMOON
The final supermoon of 2025 is the December Cold Moon, occurring on the night of December 4-5 and marking the year’s third straight supermoon. It will appear slightly larger and brighter than an average full moon and rise near prominent winter star clusters such as the Pleiades and Hyades, making it a photogenic target for skywatchers.
Aside from marginally higher-than-usual tides, this event is visually dramatic but scientifically routine, a predictable outcome of celestial clockwork rather than anything ominous.
– Ends
