The Harvest Moon is the full moon closest to the September equinox, which usually happens around September 22, depending on the year and time zone. In 2023, the Northern Hemispheres Harvest Moon fell overnight on September 28-29, almost six days after the September equinox. The Harvest Moon is unique because it rises close to the same time several days in a row, providing farmers with extra hours to harvest their crops before the first frost.

The Harvest Moon is named for the period when Northern Hemisphere crops typically reach their peak, and its bright moonlight after sunset traditionally provided farmers with extra hours to harvest their crops before the first frost. Besides its astronomical appeal, the Harvest Moon can impact weather patterns along the East Coast due to its influence on tides.

The Harvest Moon is not necessarily bigger, brighter, or more colorful than any other full moon, but its distance from Earth and apparent size in our sky differs from year to year because the moons orbit around Earth is not a perfect circle. In 2023, the Harvest Moon was a full supermoon, but not the closest supermoon for the year.

The Harvest Moon of 2023 was the last supermoon of the year, and it marked the first full moon of autumn for the Northern Hemisphere. It was also the fourth in a series of supermoons that began in July, with two in August due to the Blue Moon. The next supermoon will not occur until the next Harvest Moon in September 2024.