The official first day of fall starts on Sept. 23, but before that, a rare Harvest Moon will appear across the United States on Friday, Sept. 13.
The Old Farmer’s Almanac says the Harvest Moon is a Full Moon that starts at the fall or autumnal equinox.
“This usually means it coincides with the September full Moon, though it can also fall nearer to the October full Moon, occurring anywhere from two weeks before to two weeks after the equinox,” the website says. “In 2019, the Harvest Moon will reach its peak on Saturday, September 14, at 12:33 A.M. (EDT). For the best view, look skyward on the night of the 13th—Friday the 13th, no less!”
Meanwhile, the Almanac says that the Harvest Moon differs from other full Moons throughout the year.
“Full Harvest Moon rises at sunset and then will rise very near sunset for several nights in a row because the difference is at a yearly minimum. It may almost seem as if there are full Moons multiple nights in a row!” it says.
What also makes the Harvest Moon special is that a typical moon rises an about of 50 minutes later each night. But the Harvest Moon is only 30 minutes later than the previous day, according to the forecaster.
The Farmer Almanac noted that farmers who are still harvesting crops will get help from the Harvest Moon ahead of the fall season.
According to Newsweek, a full moon appearing on Friday the 13th is rare, and it won’t happen again for another 30 years in 2049. The last full moon to land on Friday the 13th was Oct. 13, 2000.
“The Moon may rise as little as 23 minutes later on several nights before and after the full Harvest Moon (at about 42 degrees north latitude), which means extra light at peak harvest time near autumn. By the time the Moon has reached last quarter, however, the typical 50-minute delay has returned. At the start of spring, the opposite applies. The full Moon is in the section of the zodiac that has the steepest angle with respect to the eastern horizon. For several days bracketing the full Moon nearest the vernal equinox, the delay in moonrise is as much as 75 minutes (at 42 degrees north latitude),” the Almanac also noted.