In the evening hours of May 31
The Blue Moon rises on the evening of May 31, 2026. Just like any other full moon, moonrise above the eastern horizon is the most impressive moment, when the moon illusion makes it appear especially large.
Blue Moon 2026: Why the Full Moon on May 31 Is Special
May 31, 2026 brings a Blue Moon. That does not mean the Moon glows blue — it means it is the second full moon within a single calendar month. May 2026 therefore has a remarkable full-moon line-up: the Flower Moon on May 1 and the Blue Moon on May 31.
- Date: May 31, 2026
- Event: Blue Moon
- Type: monthly Blue Moon
- Meaning: second full moon in May 2026
- Colour: the Moon does not normally appear blue
- Visibility: easily visible worldwide in clear skies
Why Is It Called a Blue Moon?
The name comes from the English idiom "once in a blue moon", which describes something that happens only rarely. The term has nothing to do with the Moon's actual appearance — it is purely a quirk of the calendar.
When Can You See the Blue Moon 2026?
Visibility
In clear skies the Blue Moon 2026 is easy to spot with the naked eye from anywhere in the world. You need no telescope or special equipment to enjoy the bright moonlight.
Is the Blue Moon Actually Blue?
No. A Blue Moon looks exactly like an ordinary full moon — shining in the same silvery-white and golden tones. A genuinely bluish moon is extremely rare and is caused only by particular particles in the atmosphere, for example after major volcanic eruptions or massive wildfires (as in 1883, after the eruption of Krakatoa).
Why Does May 2026 Have Two Full Moons?
A complete lunar cycle (from full moon to full moon) lasts about 29.5 days. Because our calendar months (apart from February) have 30 or 31 days, the moon phases drift forward a little each month.
When a full moon lands right at the start of a month — as on May 1, 2026 — there is enough time left at the end of the month for a second full moon, which follows on May 31. That calendar coincidence is what creates the Blue Moon.
Blue Moon, Flower Moon and Micromoon: May 2026 Explained
The first full moon in May (on May 1) traditionally carries the name Flower Moon, after the blossoming spring landscape. The second full moon on May 31 carries the additional label Blue Moon.
The May full moon is also a candidate for a "micromoon" (an apogee full moon), because in May the Moon is relatively far from Earth and therefore appears slightly smaller in the sky than average.
Frequently Asked Questions about the Blue Moon 2026
When is the Blue Moon in 2026?
The Blue Moon falls on May 31, 2026. It is the second full moon within the month of May.
What does Blue Moon mean?
A monthly Blue Moon is the second full moon within a single calendar month. The Moon does not normally look blue.
Will the Moon really be blue on May 31, 2026?
No. The term Blue Moon describes a calendar quirk. The Moon's colour does not change.
Why does May 2026 have two full moons?
A lunar cycle lasts about 29.5 days. When a full moon falls right at the start of a month, a second full moon can follow within the same month.
How rare is a Blue Moon?
A Blue Moon is rare but not unique. It arises from the overlap of the lunar cycle with our calendar system.
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