Harvest Moon 2021 on Sept. 20 falls in summer, which might seem as out of place as pumpkin spice latte in 90-degree weather. But it’s not really that unusual.
The Harvest Moon is the full moon closest to the autumn equinox, which is the first day of fall on Sept. 22 this year. The name derives from the extra nighttime light the full moon at that point in the year gave to farmers working to bring in their harvests.
The equinox generally varies between Sept. 22 and 23, and the closest full moon can range from Sept. 8-Oct. 7. That means the Harvest Moon occurs in summer about half the time.
The alignment of full moons with the calendar this year set the stage for a summer Harvest Moon. There will have been four full moons this summer, as the fourth occurs on Sept. 20. The previous three occurred June 24, July 23 and Aug. 22.
While a summer Harvest Moon is about a 50-50 chance, a September Harvest Moon occurs about 76 percent of the time, according to The Farmer’s Almanac. We saw an October Harvest Moon on Oct. 1, 2020 and won’t see another until Oct. 6, 2025.
Once past the coming Harvest Moon, we can look forward to the Hunter’s Moon on Oct. 20.
