May will have two full moons, including a rare ‘blue micromoon’ ending the month. Here’s what that means.

WASHINGTON — May will have two full moons, a rarity that means that 2026 will have 13 full moons instead of the typical 12. It’s a lunar phenomenon that gives a literal meaning to the saying, “once in a blue moon.” 

The two moons each have special names. The “flower moon” will reach peak illumination on Friday afternoon at 1:23 p.m. Eastern Daylight Time. Since that’s during the day, the best chance of checking out the full moon will be on Thursday and Friday nights. 

As the saying goes, April showers bring May flowers. Coined by the Old Farmer’s Almanac, the flower moon symbolizes the springtime bloom after a harsh winter. The movie and book “Killers of the Flower Moon” are also named after this phenomenon. 

At the end of the month comes the rarer Blue Micromoon, which will light up the night sky, peaking around 4:45 a.m. EDT on May 31. 

The saying “once in a blue moon” refers to this rare phenomenon: a second moon within one calendar month. The last time this happened was in August 2023, and there won’t be another blue moon until New Year’s Eve 2028. Despite the name, the moon will not actually appear blue. According to the Encyclopedia Britannica, the phenomenon got its name after the famous Krakatoa eruption of 1883. Many believe that “The Scream,” the famous Edvard Munch portrait of existential dread is an accurate depiction of the skies over Norway after the volcano’s eruption. 

The micromoon makes the phenomenon this year even rarer, as the full moon will appear smaller than usual. This year’s flower moon is also considered a micromoon. 

Also called a minimoon, a micromoon happens when the full moon coincides with the moon’s orbit taking it to the furthest point it reaches from the earth. Because it will be roughly 400,000 km away from the planet during the Blue micromoon, the moon will appear up to 14% smaller and about 30% dimmer than normal. 

A micromoon happens about once every year, and is usually visible to the naked eye. 

The next full supermoon, when the full moon appears larger than usual, will be visible on Nov. 23.