The full moon of May 2026 arrives this Friday, May 1, and will be one of the most sought-after astronomical events of the month.
Not because of astrological predictions or supposed effects on the signs, but for a much more interesting reason from a scientific point of view: May begins and ends with a full moon. The first will be the so-called Flower Moon and the second, on May 31, will be a Blue Moon, a name given to the second full moon within the same calendar month.
The exact full moon phase will occur on May 1 at 17:23 UTC, which in peninsular Spain corresponds to 19:23. That does not mean you have to look at the sky right at that time to see it: the Moon will appear practically full during the nights close to the full moon, especially when it rises above the horizon after sunset.
What time is the May 2026 full moon
The full moon of May 2026 reaches its maximum illumination this Friday, May 1st at 7:23 PM in Madrid and peninsular Spain. In astronomical terms, the full moon occurs when the Sun and the Moon are on opposite sides of the Earth and the visible face of the satellite is completely illuminated from our perspective.
To observe it, it is best not to obsess over the exact minute, but to look for a place with a clear horizon, little light pollution, and good visibility to the east or southeast at the beginning of the night. The full Moon is the only phase in which the satellite remains visible practically all night, rising near sunset and setting near sunrise.
Why it's called the Flower Moon
The full moon of May is traditionally named the Flower Moon because it coincides with the moment of maximum spring bloom in much of the Northern Hemisphere. It is a popular name, not a scientific category, but it has become established in popular astronomy calendars to identify the full moon of this month.
It can also appear with other traditional names, such as Milk Moon, Hare Moon, Planting Moon, or Sprouting Moon, all linked to agricultural, seasonal, or natural cycles. The important thing: none of these names imply that the Moon changes color, size, or physical behavior in a special way that night. They are cultural designations associated with the natural calendar.
May 2026 will have two full moons
The great astronomical rarity of the month is not only in the Flower Moon, but in that May 2026 will have two full moons. The first arrives on May 1st and the second will occur on May 31st at 08:45 UTC, that is, at 10:45 AM in peninsular Spain.
This happens because the lunar cycle lasts approximately 29.5 days, while some calendar months have 30 or 31 days. If a full moon falls right at the beginning of a long month, it may allow time for another to occur before that same month ends. This is what will happen in May 2026.
What is a Blue Moon
The second full moon of May, scheduled for May 31, will be a Blue Moon. The name may be misleading: it does not mean the Moon will appear blue. In its most common use, a Blue Moon is simply the second full moon within the same calendar month.
NASA precisely recalls that the Blue Moon at the end of May will not be seen as blue; the term refers to its rarity within the calendar. May will thus close with a second unusual full moon, after having started with the Flower Moon.
May 31st Blue Moon will also be a Micromoon
The second full moon of the month will have another astronomical detail: it will be a micymoon. This occurs when the full moon coincides with a position relatively far from Earth in its orbit, so it may appear somewhat smaller and less bright than an average full moon. Timeanddate calculates that the full moon of May 31 will be about 406,135 kilometers from Earth.
The difference, however, will not be spectacular at first glance. A microluna can be seen approximately 6% or 7% smaller than an average full moon, but the human eye hardly perceives the change without direct comparison.
Furthermore, when the Moon is near the horizon it can appear larger due to an optical effect known as the lunar illusion.