The Blue Moon of May 31, 2026
Sunday 31 May · 6:45 PM AEST · Full Moon in Sagittarius
A second look
Most months get one full moon. May 2026 gets two.
The first arrived on May 1 — the Flower Moon in Scorpio, deep and intense, the kind of full moon that makes you face what you’d rather not. Now, exactly twenty-nine and a half days later, the moon swells full again. The same month, a different sign, a different question. This is a Blue Moon: the second full moon in a single calendar month, an event that comes around roughly once every two or three years.
The name has nothing to do with colour. “Once in a blue moon” — meaning rarely — is centuries older than the calendar quirk it now describes. The phrase belongs to that small group of expressions that survive long after their original meaning is lost. We say it to mean almost never, and the moon obliges by showing up just often enough to keep the saying honest.
What makes it rare
The lunar cycle — new moon to new moon — runs about 29.5 days. Calendar months run 30 or 31, except February. The maths doesn’t quite line up. Most months, that half-day overlap doesn’t matter. But every so often a full moon falls on the 1st or 2nd of a month, leaving just enough room for a second full moon to squeeze in before the month ends.
That’s what’s happening this May. The Flower Moon arrived at 3:23 AM on May 1 (AEST). The Blue Moon arrives at 6:45 PM on May 31. Two full moons, twenty-nine and a half days apart, both technically belonging to May.
The astrology of the doubling
A single full moon is illumination. Here’s what’s been growing in the dark — look at it. A Blue Moon is illumination twice. Here’s what you saw last time. What did you do with it?
The first full moon of May fell in Scorpio — the sign of buried things, intimate truths, the parts of yourself you only half-acknowledge. Whatever surfaced on May 1, you’ve been carrying for four weeks. Maybe you acted on it. Maybe you let it slip back under.
This second full moon falls in Sagittarius — Scorpio’s neighbour and opposite in temperament. Where Scorpio whispers, Sagittarius declares. Where Scorpio probes the depths, Sagittarius reaches for the horizon. Sagittarius is the truth-teller of the zodiac, the philosopher, the one who would rather say the uncomfortable thing than keep an easy peace.
A Sagittarius Full Moon asks: what’s the truth here? Not the polite version. Not the version that protects everyone’s feelings. The actual one. Coming twenty-nine days after a Scorpio Full Moon, the question becomes pointed. Whatever truth Scorpio gave you last month is now standing in front of you with arms crossed, waiting for an answer.
How to mark it
Blue Moons reward attention. You don’t need ritual tools, just willingness.
Step outside between 6 and 8 PM on Sunday 31 May. The moon will be rising in the east, large and luminous because she’s near apogee — her farthest point from Earth this orbit, technically a Micromoon, though she’ll still command the sky.
Bring something to write with. Ask yourself, plainly:
What did I learn about myself in May? What have I been avoiding saying out loud? What truth, told now, would set the next month free?
Write the answers down. Don’t share them yet. Let the moon witness what you know.
Then, when the night settles, go to bed early. Sagittarius Full Moons are not party moons. They’re declaration moons. The party can wait until you’ve told yourself the truth.