Next supermoon: Beaver Moon

What is a supermoon?

A supermoon is a full moon that happens when the Moon is near perigee, the closest point of its orbit to Earth. Because it is closer, it looks a little wider and noticeably brighter than an ordinary full moon. The opposite, a full moon near apogee, is sometimes called a micromoon.

There is no official astronomical definition, and that is why supermoon lists disagree. The word was coined in 1979 by the astrologer Richard Nolle, who defined it as a new or full moon that occurs when the Moon is within 90% of its closest approach to Earth in a given orbit. Under that rule three or four full moons in a row often qualify. Other sites use a fixed distance, commonly somewhere around 360,000 to 362,000 km.

Our rule is a fixed line: a full moon closer than 362,500 km (measured centre of Earth to centre of the Moon) is a supermoon, and one farther than 405,000 km is a micromoon. A fixed line means a supermoon on this site is always genuinely close, and the label never depends on how far the Moon happened to swing that particular month. By this rule there are 3 supermoons in 2026, 1 in 2027 and 3 in 2028. The February 2027 full moon, at 363,296 km, just misses our line but would count under Nolle's 90% rule.

Perigee and apogee: why the distance changes

The Moon's orbit is an ellipse with Earth near one end, not at the centre. Its average distance is about 384,400 km, but each month it swings between perigee and apogee. Those extremes are not fixed either: the Sun's gravity stretches and squeezes the orbit, so perigees that coincide with a full or new moon are the deepest. Between 2026 and 2028 the closest perigee is 356,641 km on December 24, 2026 and the farthest apogee is 406,597 km on January 7, 2027.

The full moon lands about one month further around the orbit each time, while the orbit's long axis slowly turns (once every 8.85 years). The result is a rhythm: full moons get closer for several months, cluster near perigee as a run of supermoons, then drift out toward apogee about seven months later. In 2026 the biggest full moon is the Cold Moon and the smallest is the Flower Moon.

How much bigger and brighter is a supermoon?

The Moon's apparent width shrinks in proportion to its distance, and its brightness falls with the square of the distance. Working it out for the real numbers:

• The next supermoon (Beaver Moon, 360,754 km) is 7% wider and 14% brighter than a full moon at the average distance.
• The biggest full moon of 2026 is 14% wider and 30% brighter than the smallest, 33.5 arcminutes across against 29.4.
• For comparison, the Moon's width at the average distance is 31.1 arcminutes, a little over half a degree, about the size of a pea held at arm's length.

Those differences are real but hard to notice. Your eye has nothing to measure the Moon against, and a full moon a month earlier is long forgotten. The brightness difference is easier to sense on a clear night away from street lights: shadows are a bit crisper and the landscape a bit brighter.

Why the Moon looks huge near the horizon

The giant orange Moon in many supermoon photos is mostly the Moon illusion plus a long telephoto lens. When the Moon rises behind trees and buildings, your brain judges it against them and reads it as enormous. Measure it and it is no wider than when it is high overhead. It is in fact slightly smaller at the horizon, by about 1.7%, because you are standing roughly one Earth radius (6,378 km) farther from it than when it is straight above you. The illusion works on every full moon; a supermoon simply gives photographers a reason to go out.

The orange colour at moonrise is real. Low in the sky, moonlight passes through far more air, which scatters away blue light and leaves the warm colours, the same effect that makes sunsets red.

Supermoons and tides

Tides are where a supermoon has a measurable effect. The Moon's tide-raising force grows with the cube of its closeness, so the closest full moon of 2026 pulls about 25% harder than an average full moon. At full and new moon the Sun and Moon also pull in line, giving spring tides. When the two coincide you get perigean spring tides, sometimes called king tides.

In practice the extra height is modest, typically a few inches beyond a normal spring tide, depending on the coastline. It matters when it lines up with a storm surge or strong onshore wind, which is when low-lying streets and coastal paths flood. Check your local tide tables rather than the Moon if you live near the shore. Despite frequent headlines, there is no useful link between supermoons and earthquakes.

The Christmas Eve 2026 full moon

The last full moon of 2026, the Cold Moon, is exactly full at 1:28 AM UTC on December 24, 2026. That is Wed, Dec 23, 8:28 PM where you are. At 356,729 km it is a supermoon by our rule, and the biggest full moon of the year: perigee follows only about 7 hours later, at 356,641 km.

Is it really a Christmas Eve full moon? It depends on your time zone. In Europe, Africa, Asia and Australia the exact moment falls on December 24. In the Americas it is still the evening of December 23. Either way the Moon looks full on both nights, so anyone outdoors on Christmas Eve sees a brilliant, nearly full supermoon. In the Northern Hemisphere it also rides very high: midwinter full moons sit where the summer Sun does, and from New York this one climbs to about 76° above the horizon.

A full moon on December 24 or 25 is uncommon. The last one on December 24 (UTC) was in 2007, the last on Christmas Day in 2015, and the next on Christmas Day is in 2034. Read more on the Cold Moon 2026 page.

Blue Moons 2026 to 2028

A Blue Moon is either the second full moon in a calendar month (the popular meaning) or the third full moon in an astronomical season that has four (the older Maine Farmers' Almanac meaning). It has nothing to do with colour or distance.

• May 31, 2026: second full moon of May 2026 everywhere, a monthly Blue Moon (and a micromoon).
• May 20, 2027: seasonal Blue Moon, the third of four full moons between the March equinox and the June solstice.
• December 31, 2028: monthly Blue Moon in time zones up to UTC+7. The December 2028 full moons fall on December 1, 2028 and December 31, 2028 in your time zone, so this one is a Blue Moon for you.

The Blue Moon of New Year's Eve 2028 is special: it is also a total lunar eclipse, with 72 minutes of totality peaking at 4:51 PM UTC. It is not a supermoon (377,592 km). It is visible from Europe, Africa, Asia and Australia; see the blood moon page for where and when.

How to see a supermoon

Look east around sunset on the night of the full moon, or the night before if the exact moment falls in the early morning. A low horizon over the sea, a lake or open fields makes the most of the rise. For a striking photo, stand well back from a landmark and use a long lens, so the Moon looks large next to it. And if clouds win, the Moon still looks almost full for a night either side.

Related: Is it a full moon tonight? · Next full moon · Moon phase today