This year, in the past nine months, we have only seen small to medium-sized full moons. However, this situation will change next month, as the full moon in October 2025, the largest of the year, will arrive first, marking the beginning of the supermoon season.
On October 6th, at 11:48 pm Eastern Time, the moon will reach its fullest phase, coinciding with the closest full moon to the autumn equinox. Traditionally, the full moon closest to the autumn equinox is called the “Harvest Moon”. This title alternates between September and October. In two out of three years, the “Harvest Moon” appears in September, but this year it falls in October during Halloween. When not referred to as the “Harvest Moon”, the full moon in October is traditionally known as the “Hunter’s Moon”, and its September counterpart is called the “Corn Moon”.
The names of the moons are rich in folklore. The “Harvest Moon” naturally refers to the time of crop harvesting, a title derived from Anglo-Saxon culture. Many other month names in the annual calendar come from Native American tribes, such as “Corn Moon” and “Hunter’s Moon”.
When the moon rises about a week later, its most notable feature will be its observable size. This time it will be a supermoon, appearing 8% larger than a typical full moon and shining 15% brighter. This phenomenon is not a visual illusion; it’s due to the moon’s orbit being more elliptical than a perfect circle, causing it to be nearer or farther from Earth at times. When the full moon coincides with the moon’s closest point to Earth (Perigee), a “supermoon” occurs.
Conversely, a “Micromoon” appears when the full moon is near the farthest point in its orbit (Apogee).
The next supermoon will be the largest of the year, followed by two slightly smaller supermoons in November and December as our largest natural satellite passes the perigee during this period. This is the supermoon season that occurs almost every year.
The “Harvest Moon” will bring some astonishing visual displays. Appearing around the autumn equinox, the moon often hangs low, closer to the horizon, often framed by buildings and trees. This prominent visual contrast can create an illusion known as the “Moon Illusion”, making the moon appear larger than usual, enhancing the impact of next month’s already huge supermoon.
The “Harvest Moon” seems to linger longer in the evening sky, as if reluctant to transition into the next lunar phase. Typically, the moon sets approximately 50 minutes later each night due to its orbit around the Earth, which is the basis for lunar phases. However, during the harvest season, the moon only delays its setting by 20 to 25 minutes each night (varies at different latitudes), providing extra moonlight for farmers to harvest crops.
This phenomenon can be explained by the moon moving northward after the autumn equinox. Although the moon’s direction of travel causes it to set later, the increasing arc of the moon rising counters this effect. The autumn equinox marks the midpoint between the shortest and longest nights of the year. As we transition into winter, the moon rises highest in the sky.
The “Harvest Moon” can also appear golden or orange in hue due to its proximity to the horizon. At this angle, moonlight must pass through more atmospheric layers to reach our eyes. Raleigh scattering filters out shorter blue wavelengths, allowing longer red and orange wavelengths to pass through. Smoke and air pollution further enhance this effect.
The “Harvest Moon” has many other names. The Old Farmer’s Almanac records several of them. For the Dakota tribes, it is called the “Drying Rice Moon” as they prepare rice during the fall. The Anishnaabe tribe refers to it as the “Falling Leaf Moon”. The Cree tribe calls it the “Migration Moon” based on the southward migration of birds. As the air turns colder, the Ojibwa and Haida tribes use appellations like “Freezing Moon” or “Ice Moon”.
For those looking to witness the spectacular Harvest Supermoon, it will reach peak brightness on the night of October 6th at 11:48 pm. However, on the nights before and after – even if not technically full moons anymore – the night sky will still showcase the magnificent sight of the supermoon, large and round.
If you miss out on next month’s astronomical event, the next supermoon will not appear until November 5th.