Full Moon names reflect the time of year they happen. And, true enough, the Harvest Moon graces the skies in the harvest season in the Northern Hemisphere.
There is also an astronomical reason why the Full Moon closest to the Autumnal Equinox is called the Harvest Moon.
The Moon rises about 50 minutes later each day, on average. At Full Moon, it rises as the Sun sets. In the Northern Hemisphere around the Harvest Moon, however, the difference in the time of moonrise from one day to the next is less than 50 minutes. At the latitude of New York City, the difference is around 25 minutes per day.
With successive moonrises coming around the same time of day, it may feel like there are several Full Moons in a row. Historically, the extra moonlight meant that farmers could work and harvest their crops for a longer time in the evenings. Hence, the Harvest Moon.
The Full Harvest Moon happens this Friday, September 29, at 5:58 a.m. EDT.
Paul
