October 2025 Full Harvest Moon: the Largest and Brightest Supermoon of the Year

Originally written by Leo S. in 2019, updated 2025

On Monday, October 6, 2025, the full Harvest Moon reaches peak illumination at 11:47 P.M. Eastern Time, but this isn’t just a regular full Moon, as it will be the first of three consecutive Supermoons in 2025, making it the largest and brightest full Moon of the year.
Rising low on the horizon, it will appear bigger, brighter, and more golden than any other Moon this year.
Because it is a Supermoon, a phenomenon occurring when the Moon is at perigee, the closest point to Earth, it will appear noticeably larger and brighter than a typical full Moon.

The Harvest Moon is the full Moon closest to the autumnal equinox (September 22 or 23) and, unlike other full Moons, it rises about the same time for several nights, providing extended evening light. Historically, this extra illumination helped farmers complete their harvests before fall frosts.
Fun fact: In 2025, October’s full Moon is closer to the equinox than September’s, so it takes the name Harvest Moon, while September’s Moon is called the Corn Moon!

But why it is called “Harvest Moon”?
For several evenings, the moonrise comes soon after sunset. This results in an abundance of bright moonlight early in the evening, which was a traditional aide to farmers harvesting their summer-grown crops.
And what makes it different from other full moons?
In short, on average, there are just a little over 12 complete Moon cycles every year (there being about 29.53 days in a synodic month), and the Harvest Moon isn’t like the other Moons. Usually, throughout the year, the Moon rises an average of about 50 minutes later each day. But near the autumnal equinox, the difference is only 30 minutes.
Additionally, the Full Harvest Moon rises at sunset and then will rise very near sunset for several nights in a row because the difference is at a yearly minimum, and it may almost seem as if there are full Moons multiple nights in a row.
For science enthusiast, the Moon’s orbital motion (combined with the larger orbit of the Earth around the Sun), carries it farther eastward among the constellations of the zodiac from night to night. At any one moonrise, the Moon occupies a particular place on the celestial sphere, but when the Earth turns toward that point 24 hours later, the Moon has moved off to the east about 12 degrees, and it takes an average of 50 minutes longer for the Earth to rotate toward the Moon and for the Moon thus to rise.
But around the date of the Harvest Moon, the Moon rises about the same time.
The zodiac is the band of constellations through which the Moon travels from night to night, and its section in which the full Moon travels around the start of autumn is the section that forms the most shallow angle with the eastern horizon.
Because the Moon’s orbit on successive nights is more nearly parallel to the horizon at that time, its relationship to the eastern horizon does not change appreciably, and the Earth does not have to turn as far to bring up the Moon.
At the start of spring, the opposite happens.

In any case, several cultures have given full Moons descriptive names based on seasonal changes, natural events, as well as human activities, helping people track the year, plan agriculture, and mark seasonal transitions.

Other traditional October Moon names include:
Hunter’s Moon, when October is not a Harvest Moon, signaling hunting season, Drying Rice Moon, a Dakota tradition, post-harvest rice preparation, but also Falling Leaves Moon, an Anishinaabe name for the transition to fall, Freezing Moon or Ice Moon, Ojibwe and Haida names marking colder temperatures, and Migrating Moon, a Cree name marking southward bird migrations.

Curious fact, it is not just Western civilization that has given special importance to the Harvest Moon.
In China, it holds a special significance: this is the season of the Festival of the August Moon (“August” is through a calendar discrepancy), or Mid-Autumn Festival (中秋節), which is held every year on the fifteenth day of the eighth lunar month.
In Chinese mythology Chang’e, the Chinese goddess of the Moon, was married to a tyrannical king, who starved his people starved and treated them brutally. The king was very afraid of death, so a healer gave him a potion that would allow him to live forever. Chang’e knew that for her husband to live forever would be a bad and terrible thing, so one night while he slept, she stole the potion. The king figured out what she had done and ordered her to return it, but she immediately drank the elixir and flew up into the sky as the moon, where she remains still today.
In any case, the Chinese Moon Festival is considered a family event, and entire families will sit up to watch the moon rise together on this night, and eat Moon Cakes in celebration.

Mooncakes are Vietnamese and Chinese bakery product traditionally, regarded as an indispensable delicacy and offered between friends or on family gatherings while celebrating the festival. They consist of a thick, tender pastry skin enveloping a sweet, dense filling, and may contain one or more whole salted egg yolks in their center as the symbol of the full moon.
There is a folk tale about the overthrow of Mongol rule facilitated by messages smuggled in moon cakes. As story goes, mooncakes were used by the Ming revolutionaries in their effort to overthrow the Mongolian rulers of China at the end of the Yuan dynasty. Apparently, the idea have been conceived by Emperor Zhu Yuanzhang and his advisor Liu Bowen, who circulated a rumor that a deadly plague was spreading and that the only way to prevent it was to eat special mooncakes, which would instantly revive and give special powers to the user. This prompted the quick distribution of mooncakes. However, the mooncakes contained a secret message: on the fifteenth day of the eighth lunar month, kill the rulers.
Another method of hiding a message was to print it on the surfaces of mooncakes (which came in packages of four), as a simple puzzle. To read the message, each of the four mooncakes was cut into four parts. The resulting 16 pieces were pieced together to reveal the message, and then eaten to destroy the message.
In any case, mooncakes remained popular even in recent years and, for many, they form a central part of the Mid-Autumn festival experience such that it is now commonly known as “Mooncake Festival”.

Well…but what is a supermoon, exactly?
Generally speaking, a supermoon is a full moon that appears larger than a typical full moon because it is closer to Earth.
However, there’s a bit more to it than that!
In fact, there are a couple of definitions of “supermoon” out there.
As a broad definition, a supermoon is a new or full moon that occurs when the Moon is near perigee, the point in the Moon’s orbit where it is closest to Earth.
By this definition, there can be several supermoons in a year.
The term, “supermoon,” was coined by astrologer Richard Nolle in 1979, who specified that the Moon must be within 90% of perigee.
On the other hand, as s strict definition, a supermoon is the single closest new moon and full moon of the year. By this definition, there can be only two supermoons each year, a full moon supermoon and a new moon supermoon.

And why do supermoons occur?
It all comes down to the fact that the Moon’s orbit around Earth is not a perfect circle, but an elliptical, oval, shape.
Because of this, the Moon’s distance from Earth changes as it travels around our planet. Additionally, Earth doesn’t sit directly in the middle of this elliptical orbit, so there are points in the Moon’s orbit where it is closest and farthest from Earth. These points are called perigee (the point in the Moon’s orbit where it is closest to Earth) and apogee (the point in the Moon’s orbit where it is farthest from Earth), respectively.
The Moon makes one complete orbit around Earth in about 29.53 days, which means it reaches its perigee and apogee points about once a month. When this occurs simultaneously as a full moon, called “perigee-syzygy” or, more commonly, supermoon!
”Syzygy” is the astronomical term for when three or more celestial bodies (such as the Sun, the Moon, and Earth) line up. When the Sun, Earth, and Moon form a syzygy, we experience a full or new moon, depending on whether the Moon is between the Sun and Earth or Earth is between the Sun and the Moon.
Although it has been all over the news in recent years, “supermoon” is not an official astronomical term. Actually, it didn’t even exist until astrologer Richard Nolle coined it in 1979.
At the time, he defined a supermoon as “a new or full moon which occurs with the Moon at or near (within 90% of) its closest approach to Earth in a given orbit.”

It sounds good but…does a supermoon really look bigger?
Given that a supermoon full moon is closer to Earth than a typical full moon, it does appear larger, about 7% larger.
This means that the difference between a full moon at perigee and a full moon at apogee can be up to 14%, which is significant.
But here’s the critical fact: unless you were somehow able to compare a normal full moon and a supermoon side by side in the sky, it’s nearly impossible to perceive a 7% difference in the Moon’s size!
Even if you could somehow place the year’s biggest possible Moon (the perigee full moon) next to the smallest one (an apogee full moon) in the sky, you’d just barely tell the difference.
In any case, if you want to be guaranteed to see a huge-looking Moon, it’s easy… Simply watch the Moon when it’s rising or setting!
A Moon down near the horizon will always look enormous, thanks to a well-known phenomenon called the Moon illusion, which makes our minds exaggerate the size of objects near the skyline.
In short, If you want a truly massive supermoon, you can have it—any night…