Here in the Northern Hemisphere, we call the full moon closest to the autumn equinox the Harvest Moon. Depending on your time zone, 2018’s autumn equinox for the Northern Hemisphere came on September 22 or 23. And the September full moon comes on the night of September 24 for the Americas, and on September 25 for much of the rest of the world. Thus, for the Northern Hemisphere, this upcoming full moon – the full moon closest to our autumn equinox – is our Harvest Moon, Earth Sky reports.
For the Southern Hemisphere, the Harvest Moon always comes in March or April.
Harvest Moon is just a name. In some ways, it’s like any other full moon name. But these autumn full moons do have special characteristics, related to the time of moonrise. Nature is particularly cooperative in giving us full-looking moons near the horizon after sunset, for several evenings in a row, around the time of the Harvest Moon.
What is a Harvest Moon? On average, the moon rises about 50 minutes later each day. But when a full moon happens close to an autumn equinox, the moon rises closer to the time of sunset. For mid-temperate latitudes, it rises only about 30 to 35 minutes later daily for several days before and after the full Harvest moon.
For very high northern latitudes, there’s even less time between successive moonrises.
The difference between 50 minutes and 35 minutes might not seem like much. But it means that, in the nights after a full Harvest Moon, you’ll see the moon ascending in the east relatively soon after sunset. The moon will rise during or near twilight on these nights, making it seem as if there are several full moons – for a few nights in a row – around the time of the Harvest Moon.
So, by all of the natural signs in the heavens, the time of autumn harvest is with us again. The term Harvest Moon traces back to preindustrial times, when farmers — lacking the technology available today — were pressed by the season and welcomed a moonlit week to stretch the shortening daylight hours. Their fields had to be harvested before the farm could be bundled up for the impending winter season. Crops had to be housed. Firewood had to be cut. The daylight hours were rapidly diminishing at this time of year; seemingly, there was not enough time for all the chores that needed to be done in the sun. The Harvest Moon was a welcome lantern in the early evening sky.
This year, it's merely a beautiful late September moon that will provide a series of bright moonlit nights at a time when the seasons are at the turn. The next full moon, on Oct. 24, will be the Hunter's Moon, traditionally touched with frost and framed in the glorious colors of autumn leaves.
The seasons march on. Summer wanes and comes to its end with this weekend's waxing moon.
And HERE is a beatiful sing about Harvest Moon by Neil Young.