What Is a Black Moon?

A “Black Moon” refers to the rare occurrence of a second new moon in a single month or the third new moon in a season with four.

This isn’t an official astronomical term, but rather folklore.

A “Black Moon” refers to the rare occurrence of a second new moon in a single month or the third new moon in a season with four.

This isn’t an official astronomical term, but rather folklore.

“It’s not official astronomy; it’s folklore. It implies that we, the people, make the decisions.”

When Is the Next One?
The next Black Moon will occur on August 22–23, 2025, depending on your time zone. I

t will reach its new moon phase on August 23 at 6:06 UTC (1:06 a.m. CDT). Like all new moons, it will be invisible from Earth since the moon’s lit side faces away from us. This creates darker skies—perfect for stargazing.

Where Did the Term Come From?
Unlike the well-known Blue Moon (a term popularized due to a 1946 misquote in Sky & Telescope), the term “Black Moon” is less defined and newer.

“I remember reading about Black Moons a few decades back in Sten Odenwald’s excellent site, The Astronomy Cafe.” It may have roots in Wiccan culture and has appeared in astronomy circles only recently. Some sources also call a month without a new moon a Black Moon, though this is even rarer.

Fun Facts

• A monthly Black Moon (second new moon in a month) happens every 29 months.

• A seasonal Black Moon (third new moon in a four-new-moon season) occurs every 33 months.

• The last seasonal Black Moon was in May 2023; the next one will be in August 2028.

• “Blue Moon is a misleading name… the moniker Black Moon is a little more true for the night sky.”