I know there’s been a lot of talk about the Moon lately, like the September full Moon being the last supermoon of the year, and recently it’s importance in the Mid-Autumn Festival or Moon Festival, but I though a little more in-depth discussion would be appropriate today since this is really the last night for the Harvest Moon. This year the Harvest Moon appears full for about three days — from September 28 to 30.
One thing that sets the Harvest Moon apart from other full Moon names is that it’s not associated with a specific month. The Harvest Moon is associated with the timing of the autumnal equinox (that occurred on September 23rd this year.) The full Moon that occurs nearest to the equinox is the one that is named “Harvest Moon.” This means that the Harvest Moon can occur in either September or October — it all depends on how the lunar cycle lines up with the Gregorian calendar. The Harvest Moon does typically occur in September, but it occasionally lands in October.
So why it it called the Harvest Moon? The first full Moon nearest the equinox, for several evenings, rises soon after sunset. This results in an abundance of bright moonlight early in the evening — that traditionally was an aid to farmers and crews harvesting their summer-grown crops. So — for that reason, it’s called the Harvest Moon.
Without getting too technical, there are just a little over 12 complete Moon cycles every year — on average. The Harvest Moon is a little different than the other Moons in that:
Usually, throughout the year, the Moon rises an average of about 50 minutes later each day (night.)
But for a few nights around the Harvest Moon, the Moon seems to rise at nearly the same time (actually, it’s just about 25 to 30 minutes later.)
And — the Harvest Moon rises at sunset and then will rise very near sunset for several nights in a row. It almost seems like there is a full Moon multiple nights.
The idea of the Harvest Moon originated in Europe (where the average latitude is about 50 degrees north and the Harvest Moon rises only 10 to 20 minutes later each night.)
It probably seemed like a bonus — just when the days were rapidly getting shorter and the Sun seemed to go down too soon, the Harvest Moon arrived to extend the hours that harvesting could be done.
As I mentioned yesterday, it isn’t just Western civilizations that gives special importance to the Harvest Moon. For Chinese people, this full Moon is the occasion for the Mid-Autumn Festival.
All full Moons are kind of neat, but the Harvest Moon is really special.
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