The Strawberry Moon is the widely recognized name for the full moon that occurs in June each year. This celestial event marks a specific time in the annual cycle of lunar phases, drawing attention from sky-watchers across the Northern Hemisphere. It is one of many traditional names given to the monthly full moons, reflecting the seasonal changes on Earth. The Strawberry Moon is defined by its timing rather than its color or form.
Defining the Strawberry Moon
The Strawberry Moon is the astronomical term for the full moon occurring in June. Its common name has nothing to do with the moon’s physical appearance or color. Instead, the moniker originates from North American Indigenous traditions, specifically among the Algonquin, Ojibwe, Dakota, and Lakota peoples. This name served as a practical, seasonal marker for the short window when wild strawberries ripened and were ready for harvest.
The full moon’s name was essentially a calendar signal, indicating that the strawberry picking season had begun in the northeastern regions of North America. Other cultures had their own names for the June full moon, such as the Rose Moon in Europe, referencing the blooming of roses, or the Green Corn Moon by the Cherokee. These varied names reflect the abundance and new life associated with the early summer season.
Analyzing the Frequency of Occurrence
The Strawberry Moon itself is not rare, as it occurs annually. Since a full moon happens roughly every 29.5 days, the cycle ensures one full moon will always fall within the calendar month of June. The June full moon is a predictable and guaranteed event in the Earth-Moon system.
However, the moon’s orbit includes a much longer, complex cycle that can make a particular viewing of the Strawberry Moon unique. This is the 18.6-year cycle known as the major lunar standstill, or lunistice, which dramatically alters the moon’s path across the sky. During the peak of this cycle, the full moon will appear at its most extreme high or low points on the horizon. The lowest-hanging full moon for nearly two decades only occurs during this specific phase of the standstill, which is a truly rare, generational event.
Understanding the Visual Appearance
Despite its fruity name, the Strawberry Moon does not inherently appear pink or red. The lunar surface reflects sunlight equally across the visible spectrum, meaning the moon itself is a shade of gray. Any warm coloration, such as gold, amber, or a reddish-orange hue, is an atmospheric effect. This visual shift is caused by light traveling through a greater thickness of Earth’s atmosphere when the moon is low on the horizon.
This phenomenon is known as Rayleigh scattering, the same process that makes sunsets appear red. Short-wavelength blue and green light are scattered away by atmospheric particles, allowing longer-wavelength red and orange light to pass directly through to the observer. Because the June full moon is the lowest full moon of the year for Northern Hemisphere observers, its light must penetrate a maximum amount of air, enhancing this reddish scattering effect. The low position also contributes to the “Moon Illusion,” which makes the moon appear significantly larger than when it is high in the sky.