It has nothing to do with cloudy skies, witchcraft, wizardry, or because there’s a New Moon on Sunday, either. So why won’t we see the moon on Halloween Night?

First of all, I’m willing to bet all of my kid’s Halloween candy that if you watch a Halloween-themed movie this weekend, it will depict the moon as full. It’s almost a guarantee in spooky cinema.

The moon will NOT be full on Halloween this year. As a matter of fact, there is only a full moon on Halloween about once every 19 years. We had a full moon on 10/31 last year…and it was a Full Blue Moon, which was quite rare. There won’t be another Full Blue Moon on Halloween again until 2039. Prior to last year, we hadn’t seen a Full Blue Moon on Halloween since 1974.

(There will be four more chances this century to see a full moon on Halloween: 2039, 2058, 2077, and 2096.)

So, if there is not a New Moon on Sunday, why won’t we see it when we’re out trick-or-treating?

It’s not witchcraft or wizardry. It’s simply because the moon will set in the western sky just before 4:30 in the afternoon on Sunday.

timeanddate.com

Next year, however, the moon will be nearly half full and will be nearly directly overhead while the kids are out and about.

If you truly want a spooky moon on Halloween, look for a “Black Moon" -- when there's a second New Moon in a calendar month. The next time there's a Black Moon on Halloween won't be until the year 2035 and it hasn't occurred since 1997.

LOOK: How Halloween has changed in the past 100 years

Stacker compiled a list of ways that Halloween has changed over the last 100 years, from how we celebrate it on the day to the costumes we wear trick-or-treating. We’ve included events, inventions, and trends that changed the ways that Halloween was celebrated over time. Many of these traditions were phased out over time. But just like fake blood in a carpet, every bit of Halloween’s history left an impression we can see traces of today.

LOOK: 34 spooky dessert recipes for this Halloween