Sky watchers are preparing for a unique lunar event this weekend as a “monthly Blue Moon” rises on Sunday, May 31, 2026.
This phenomenon occurs when two full moons appear within a single calendar month, a quirk made possible because the moon’s cycle is approximately 29.5 days – slightly shorter than most months.
While the term might suggest a color change, experts clarify that the moon will retain its familiar appearance. As the Farmer’s Almanac notes: “The Moon will not actually be the color blue, so don’t be disappointed.”
Astronomers explain that the Moon only appears blue under extremely rare atmospheric conditions, such as when volcanic dust or wildfire smoke scatters light in the upper atmosphere.
This particular event is also classified as a “micromoon” because it occurs near apogee, the point in the moon’s orbit farthest from Earth.
This makes it the smallest full moon of the year appearing roughly 5.5% smaller and 10.5% dimmer than an average full moon.
Despite the scientific nuances, it remains a rare and beautiful sight. As one observer might put it:
“Once in a Blue Moon still captures our imagination,” serving as a simple, elegant reminder of the cosmic mechanics governing our night sky.
