A “blood moon” (total lunar eclipse) happens roughly every 1–3 years somewhere on Earth, but any given location will usually see one only every few years.

What a “blood moon” actually is

  • A blood moon is just a total lunar eclipse, when Earth’s shadow completely covers the Moon and sunlight passing through our atmosphere makes it look red or coppery.
  • Not every full moon does this; the Moon’s orbit is tilted, so the alignment only happens occasionally.

How often it happens (globally vs where you live)

  • Lunar eclipses of all kinds (partial, penumbral, total) happen about 2 times a year on average.
  • Only about 29% of these are total eclipses, so true “blood moons” average about once every 1–3 years worldwide.
  • From any one place on Earth, you’ll typically see 4–5 total lunar eclipses in a decade, so your local blood moons feel more like “every couple of years.”

Think of it like this: somewhere on Earth a blood moon shows up fairly regularly, but you, standing in one spot, are only under the “spotlight” for some of them.

Extra: those “four blood moons in a row”

  • Sometimes there’s a series of four total lunar eclipses in about two years; this is called a lunar tetrad.
  • Tetrads are much rarer than single blood moons and tend to cluster in certain centuries; for example, 1909–2156 has many tetrads, while 1582–1908 had none.

Quick FAQ style recap

  • How often is there some blood moon on Earth?
    • Roughly every 1–3 years, depending on how the eclipses in that period line up.
  • How often will I personally see one?
    • Around once every few years, adding up to maybe 4–5 in a decade from your location.
  • Are they rare?
    • Single blood moons are not very rare; long gaps can happen in specific locations, but globally they’re fairly regular.

TL;DR: Total lunar eclipses (blood moons) occur on Earth about every 1–3 years, but from where you live you’ll usually catch one only every few years.

Information gathered from public forums or data available on the internet and portrayed here.