The Pink Moon is the widely recognized name for the full moon that occurs in April. This traditional designation marks the beginning of spring in the Northern Hemisphere, following the March equinox. The name is not an indicator of the moon’s actual color, but simply refers to the full moon that falls within April each year.
Why the April Full Moon is Called the Pink Moon
The origin of the Pink Moon name is entirely terrestrial, drawing from the traditional naming systems of Native American tribes, particularly the Algonquin peoples. These names were historically used to track the seasons and the cycle of nature rather than astronomical events. The common name is specifically connected to the early spring bloom of a particular wildflower native to the eastern United States.
This plant is the moss pink, or Phlox subulata, a low-growing, creeping ground cover that produces widespread blankets of pink or mauve flowers. The appearance of this vibrant bloom coincided with the arrival of the full moon in April, prompting the people to name the moon after the flower. While the Algonquin names for the April full moon varied across different tribes, the one associated with the pink flower became the most widely popularized.
Other Native American names for the same moon reflected different seasonal events, such as the Sprouting Grass Moon, the Egg Moon, or the Fish Moon, marking the return of fish upstream to spawn. The Maine Farmer’s Almanac began publishing and popularizing this list of full moon names in the 1930s, which helped the Pink Moon designation enter the broader public vernacular.
The Visual Appearance and Common Misconceptions
Despite its name, the Pink Moon does not appear pink to the naked eye. This is a common misconception, as its coloration is no different from any other full moon throughout the year. The moon reflects sunlight, giving it a typical silvery white, yellow, or golden hue.
Any perceived coloration of the moon is due to atmospheric scattering of light, not a change in the lunar surface itself. When the full moon is low on the horizon, its light travels through a greater thickness of Earth’s atmosphere, which scatters blue light more effectively. This effect can leave the moon appearing amber, orange, or sometimes a pale reddish color. Dust, smoke, or pollution in the air near the horizon can also amplify these tinting effects, but they are unrelated to the Pink Moon’s specific name.
Calculating the Timing of the Pink Moon
The timing of the Pink Moon is determined by the precise astronomical moment when the moon reaches its full phase. This occurs when the Earth is positioned almost directly between the sun and the moon, causing the side of the moon facing Earth to be fully illuminated by sunlight. Although the moon may appear full for about three days, the exact moment of fullness, or peak illumination, lasts only an instant.
The Pink Moon is the first full moon that follows the vernal equinox, which occurs around March 20th. This full moon is also sometimes called the Paschal Full Moon, as its timing is used to determine the date of Easter Sunday. Since the lunar cycle averages 29.5 days, the full moon can fall on various dates within April.