Rare Blue Moon Coming This Weekend - And It Won't Be Back Until 2028

The month of May is bookended by two full moons this year, creating a rare celestial event that won't be seen again until 2028.

The second full moon is commonly referred to as a blue moon. It's not actually blue in color, but is technically called a calendrical or monthly blue moon.

The rare astronomical phenomenon will be visible on May 31.

What Is A Blue Moon?

A seasonal blue moon is the third of four full moons in an astronomical season, which is dictated by solstices and equinoxes and usually has only three full moons, per the Old Farmer's Almanac.

"The modern understanding of ‘blue moon' only took off in the 1980s," reports the almanac. "It was a result of a much earlier mistake printed in a 1946 issue of Sky & Telescope magazine, and since then, the term has gone viral in the media."

The term "once in a blue moon" was sparked, though, this celestial event will take place again in 2028 - as it happens every two and a half year on average.

What Makes This Blue Moon Special?

While blue moons emerge every 2.5 years, this year's spectacle will be the smallest full moon of 2026.

Compared to an average full moon, Earth's satellite will seem around 6 percent smaller and 10 percent dimmer during this micromoon, Gianluca Masi, an astronomer and founder of the Virtual Telescope Project, told the Associated Press' Marcia Dunn.

While that's a significant percentage given the scale of the moon, Masi admitted viewers aren't likely to notice with the naked eye.

USA Today's Julia Gomez revealed the last monthly blue moon was on August 19, 2024 and in that case it was a super blue moon.

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This story was originally published by Men's Journal on May 29, 2026, where it first appeared in the News section. Add Men's Journal as a Preferred Source by clicking here.

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This story was originally published May 28, 2026 at 6:35 PM.