Blue Moon May 31, 2026MicromoonBlue Moon

When the Blue Moon peaks, how far away and how bright it is, and how good the view will be.

An image of the moon, as it would appear on 2026-05-31 12:00:00+00:00. (Frame: 3613)

Rendering: NASA’s Scientific Visualization Studio

Full moon
May 31, 2026
Illumination
100%
Distance
406,203 km
Apparent size
micromoon
80
View score: Excellent

A premier night to look up, sky permitting.

  • 100% illuminated
  • micromoon — smaller, dimmer disc

About the Blue Moon

On May 31, 2026, the full phase peaks—this one is the May full Moon, nicknamed for the springtime bloom.

It doubles as a Blue Moon, the second full Moon inside a single calendar month. The term is a calendar quirk, not a hue: the 29.5-day lunar span is a hair shorter than most months, so about every two to three years one month grabs two full moons.

Full phase marks the point in the roughly 29.5-day cycle when the Moon stands opposite the Sun; the Earth-facing hemisphere is fully lit. It rises near sunset, climbs highest by midnight, and sets near sunrise, remaining visible all night if skies are clear.

How to see the Blue Moon

At 405,808 km from Earth, the Blue Moon qualifies as a micromoon. It lands close to apogee—the orbital far point—so its disk looks a touch smaller and fainter than average.

Catch it early on May 31, 2026, just above the eastern horizon after sunset. When low, foreground objects trick the eye into perceiving a larger, more colorful disk. Naked-eye is enough, though binoculars reveal extra detail along the day–night border during the nights before and after.

Frequently asked

When is the Blue Moon in 2026?
The Blue Moon reaches full phase on May 31, 2026. It rises around sunset that evening and stays visible through the night.
Why is it called the Blue Moon?
The name reflects only the calendar: it is the second full moon within a single month. Color is unchanged.
What is a full moon, exactly?
A full moon occurs once each roughly 29.5-day cycle, at the instant the Moon sits opposite the Sun. To the eye it appears full for about a night on either side of that moment.

Every full moon in 2026

See the full 2026 full moon calendar, or the sunset & twilight times for golden-hour planning.