How Rare Is a Halloween Full Moon? | The Old Farmer's Almanac

How Rare Is a Full Moon on Halloween?


A Halloween Full Moon May Be Spookier Than You Think!

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Ever noticed that Halloween pictures always show a full Moon? How rare is a full Moon on Halloween, exactly? Let’s learn more about the mythical Moon on this rather mystical night! 

How Rare Is a Halloween Full Moon?

Despite all the creative Halloween full Moon pictures, a full Moon occurring on Halloween is not a common occurrence and only happens every 18 to 19 years. The last time a full Moon happened on Halloween night was in 2020, so don’t expect another for quite a while! 

As you know, Halloween always occurs on October 31; it’s only the day of the week that changes from year to year. Given that a lunar cycle (the time it takes for the Moon to go through one full cycle of its phases) lasts about 29.5 days, if there is a full Moon on Halloween, it will also be the second full Moon in October and, therefore, a Blue Moon

Halloween Origins

The origin of Halloween itself can be traced back to Samhain (pronounced SOW-in, which rhymes with COW-in), which was an ancient Celtic festival that was celebrated to mark the end of harvesttime. It was also the end of their year and the beginning of the new year, so it was “in between” the two years. It’s said that the spirits of the dead wander around during this time in the moonlight. Learn more about the origins of Halloween traditions.

Halloween full moon with bats

A New Moon on Halloween

For a truly spooky night, look to the new Moon, when darkness reigns. During this Moon phase, the lunar disk goes black, so the night appears “moonless.” Of course, the Moon is there, but it’s not lit up by the Sun due to its position in its orbit. See more about the so-called dark side of the Moon.

The Moon will be between 0% and 1% illumination on Halloween in 2024, depending on your timezone. See our Moon Phase Calendar—customized by zip code.

The Black Moon

An even rarer oddity is a “Black Moon.” Although this is not technically an astronomical term, “Black Moon” has come to mean the second new Moon in a calendar month. (It’s somewhat the opposite of a “Blue Moon,” which is popularly defined as the second full Moon in a month.) Read more about the Black Moon.

Full Beaver Moon

First Full Moon After Halloween

The first full Moon after Halloween is November’s Moon, which is traditionally called the Full Beaver Moon. According to the Algonquin tribes (and early colonists), this was the time to set beaver traps before the swamps froze, to ensure a supply of warm winter furs.

If you carefully observe nature, you might notice that there are certainly patterns and traditions that happen during the first full Moon after Halloween.

  • The full Moon after Halloween is thought to be a time when the deer rut (mating season) is in full force.
  • Our readers share that it’s the time when snow geese arrive at Chesapeake Bay in lower Delaware and Maryland.
  • For many folks, garlic is planted after the first few days of Halloween’s full Moon.
  • According to folklore, it’s best to dig sweet potatoes from the ground during the full moon of November.

What would you name the first full Moon after Halloween? Post your comment below!