Rare lunar event set to light up Welsh skies this month

Nation.Cymru staff

A rare “once in a blue moon” double lunar event is set to light up Welsh skies this month.

On Sunday May 31st, a blue moon will rise in the sky. Unlike most months where there is only one full moon, it will be the second full moon in a calendar month following the flower moon on May 1.

Although the moon will not appear blue in colour, the event is special because it only occurs around every two or three years.

It will also be a “micro moon”or “mini moon”, which occurs when the moon is at its farthest point from Earth (252,360 miles away) making it the most distant and smallest full moon of 2026.

A micro-moon is the opposite of a super moon which happens when the moon is at its closest point.

It will look around 7% smaller and will be dimmer than a typical full moon, though this difference can be subtle to the naked eye.

Antonella from Psychic World said: “While the micro moon may appear smaller than usual, the UK’s beautiful natural landscapes offer a chance to see it at its best, whether it is rising over ancient monuments, mountain peaks, or dark sky reserves, there are multiple ways to enjoy this once in a blue moon event.”

Clear skies are essential for good viewing of the lunar event, especially that of the micro moon which can be easily obscured by clouds.

Moon watchers should be sure to check weather forecast in advance and aim for locations with minimal haze or humidity.

Timing is crucial to spot this event, the moon will appear at its best and most visible just after it rises or before it sets, when it’s closer to the horizon.

Striking

Plan to head out shortly after sunset and before moonrise for the most striking view.

Because a micro moon is less bright than a typical full moon, darker surroundings make a big difference.

Therefore, heading to more rural areas can help ensure there will be limited artificial light washing out the view.

Although it will still be visible to the naked eye, a micro moon can really benefit from magnification.

Binoculars or a camera with a zoom lens can help reveal that extra beauty and detail on the lunar surface and enhance the overall experience.

You may be able to see this moon from your garden in Wales as long as the sky is clear enough and you have an open view.

It will look like a normal full moon, with no obvious colour difference to the naked eye.

The best time to look is around moonrise just after sunset, when it is easiest to spot and appears at its brightest.

Dark skies

At 1,085 metres high, Yr Wyddfa, offers unparalleled views, making it a perfect spot for watching the moon.

As an official International Dark Sky Reserve, the park provides exceptionally dark skies, which are vital for seeing the micro moon at its best.

It offers some of the best viewing angles in the UK for rare lunar events and the elevated, extensive landscape provides a stunning backdrop for photography too.

Garwnant in Bannau Brycheiniog National Park also offers low light pollution, making it an ideal place for viewing lunar events, the Milky Way and constellations.

Orbit

May’s blue moon will occur because the lunar calendar does not perfectly match the calendar months we use on Earth.

The moon orbits Earth roughly every 29.5 days, while most months have 30 or 31 days.

While our calendar year lasts 365 days, and 366 in a leap year, 12 lunar cycles add up to only around 354 days, leaving a noticeable gap each year.

As a result, every two to three years, there is a 13th moon, dubbed a blue moon.

In 2018, there were two blue moons in a single year – a rare occurrence that will not happen again until 2037.

There are two kinds of blue moon: seasonal and monthly.

Seasonal blue moons follow the astronomical season marked by solstices and equinoxes.

During this time we usually see three moons – but because the moon cycles are not always perfectly aligned with these seasons, we sometimes get four moons.

There will be a blue moon in 2027, but unlike this month’s blue moon – it will be a seasonal blue moon.