What Is A Harvest Moon? | High Point Scientific

There are a lot of names given to the Moon these days. Whether it’s a New Moon, Old Moon, Blood Moon, Super Moon, Blue Moon, or Black Moon, it appears as though there’s a Moon for every occasion. One of these - the Harvest Moon - has been around for hundreds of years and has been commemorated throughout the world. So what is a Harvest Moon?

What is the Harvest Moon?

The Harvest Moon is aptly named. Not surprisingly, it’s so-called because its light allowed farmers to harvest their crops during the night. Being the full Moon, it rises at sunset and then sets at sunrise, so even though the days are drawing shorter, the moonlight provides valuable additional hours for the farmers to do their work.

Image Credit: NASA

While European farmers toiled in the fields, Asian cultures held celebrations on the 15th day of the eighth lunar month of the year. On this date, which coincided with the Harvest Moon in Europe, families would gather and share food, exchange gifts, and enjoy festivals - a practice that still continues today.

The Harvest Moon is always the full Moon that occurs closest to the autumnal equinox. Since this occurs in late September, the Harvest Moon usually falls in that month, but it sometimes falls within the first week of October instead.

Every month has a full Moon and each full Moon has a different name. For example, September’s full Moon is the Corn Moon, whereas October’s is often called the Hunter’s Moon. However, when a month’s full Moon is closest to the autumnal equinox, it becomes known as the Harvest Moon instead.

The timing of the Harvest Moon is fortuitous as it provides extra moonlight for a number of nights. During the rest of the year, the Moon will typically rise about 45 minutes later each night. However, the autumnal equinox is when the path of the Sun, Moon, and planets (called the ecliptic) is most shallow in relation to the horizon.

As a result, there’s a shorter interval between moonrise on one night and moonrise on the next. Instead of having to wait an additional 45 minutes for the Moon to rise the following night, farmers found they only needed to wait another 10 or 15 minutes instead. (The effect is more pronounced the closer the full Moon is to the equinox and the further north you go.)

When is the Harvest Moon?

In 2022, September’s full Moon occured on September 10th. It therefore becomes the Harvest Moon and October’s full Moon remains the Hunter’s Moon. However, in 2025, the Moon turns full late in the evening of October 6th for North American observers. This makes it the Harvest Moon, while September’s Moon is known as the Corn Moon.

The earliest a Harvest Moon can occur is September 8th. This occurs four times in the 21st century for North American observers: 2014, 2033, 2052, and 2090. At the opposite end of the scale, the latest a Harvest Moon can occur is October 7th, which happens four times overall (2006, 2025, 2044, and 2063), but only the last occurs on the 7th for North American observers.

(The rest all occur in the early hours of the 7th, which would be the 6th for anyone in the U.S. or Canada.)

Whenever the Harvest Moon next occurs, and wherever you might be, take a few moments to step outside and enjoy the moonlight!