What makes September’s full moon so special? The Harvest Moon, September’s full moon, will appear big and bright because the Moon will be at the closest point in its orbit to Earth. In September, the Moon’s orbit aligns with our eastern horizon, making it so the moon rises at sunset. Because of this, the Moon gives farmers extra light to work into the night in September, which is why the month’s full moon is called the Harvest Moon! This full moon falls on September 17, when there also happens to be a partial lunar eclipse!