The traditional full moon name for September is the “Harvest Moon”. The Harvest Moon is somewhat unique in that it is assigned to the full moon closest to the autumn equinox. That means it can also be the name of the full moon in October. The Harvest Moon name is obviously a reference to farmers working late into the night harvesting crops by the light of the full moon.
The Moon also rises at a steep angle giving the Moon more time above the horizon and much shorter times between moonrises and sunsets.
Other names include the “Fruit Moon”, “Dying Grass Moon”, "Wine Moon", "The Singing Moon", "Blue Corn Moon", "The Elk Call Moon", and “Barley Moon”. The Lakota Sioux called it the “Moon where Calves Grow Hair” or “Moon when Plumes are Scarlet”. The Taos call it “The Yellow Leaf Moon” and the Oto call it “Spider Web on the Ground at Dawn Moon”.
Technically the full moon is only a moment in time. That moment occurs at 5:14am MDT on Thursday, September 19. The Moon will look full on the evenings September 18, September 19, and September 20. So when observing the Moon which is closest to the true full moon? There is an easy way for the casual observer to tell. A full moon always rises (east) opposite the setting Sun (west). In general, the Moon that rises within a half hour of sunset is closest to the full moon. If the Moon is well above the horizon or has not risen until well after (greater than a half hour) sunset, it is not a full moon even though it looks like one. Let’s see what the data shows this month for Aurora, CO.
September 18 The Moon rises well before sunset
Sunset: 7:04pm MDT
Moonrise: 6:27pm MDT
Difference: 37 minutes (Failed, Moon and Sun are not opposite but close)
September 19 The Moon rises within 30 minutes of sunset
Sunset: 7:02pm MDT
Moonrise: 7:01pm MDT
Difference: 1 minute (Pass Moon and Sun are opposite)
September 20 The Moon rises within 30 minutes of sunset
Sunset: 7:00pm MDT
Moonrise: 7:35pm MDT
Difference: 35 minutes (Pass Moon and Sun are opposite)
This test works most every time for any full looking moon.
A full moon is the only time the Moon is up all night and the only time a lunar eclipse can take place. A full moon also sets in the west opposite the rising Sun providing us living near the front range really spectacular moonsets over the mountains, easily noticed by early morning west-bound commuters.
This month the Moon will be closer to full on the morning or September 19. Moonset will occur at 6:56am MDT. Sunrise occurs at 6:44am MDT. You want to start watching before 6:20am MDT. You can observe the sunrise before the moonset. They are usually pretty good here in Colorado.
If you happen to be a bicycle rider you may was to try the New Harvest Moon Triathlon Bike Course near Aurora, CO by the light of the harvest moon. Note also Aurora will be hosting Harvest Moon Triathlon Race and Festival on September 8.
Wishing you clear skies