The Buck Moon is the traditional name given to the full moon that occurs annually in July, marking the middle of summer in the Northern Hemisphere. This name is part of a series of popular names assigned to each month’s full moon, often originating from various Indigenous cultures and early European settlers who tracked the seasons. Although the July full moon does not appear physically different from any other full moon, its name is tied to a specific natural occurrence of the season.
The Origin of the Name
The name “Buck Moon” originated primarily with the Algonquin tribes of North America, who used the natural world, including the full moon, as a reliable seasonal marker. The July moon signaled a specific period in the annual cycle of the male deer, or buck.
Male deer shed their antlers completely each winter and begin regrowing them during late spring and early summer. By July, these new antlers are in a rapid growth phase, still coated in a soft, fuzzy layer of skin and blood vessels called velvet. This noticeable stage of antler development, where the buck’s headgear is fully visible, became the defining characteristic for naming the midsummer full moon.
Astronomical Timing and Visibility
The Buck Moon, like all full moons, is an astronomical event defined by the moment the Earth passes between the Sun and the Moon. This alignment causes the Moon’s Earth-facing side to be completely illuminated. Although peak illumination occurs at a precise moment, the moon appears completely full to the naked eye for about three days.
For observers in the Northern Hemisphere, the July full moon follows a relatively low arc across the sky. This lower trajectory is a consequence of the summer season, mirroring the path of the winter sun. The lower altitude means the moon spends more time near the horizon, which can enhance the Moon Illusion.
The Moon Illusion
The Moon Illusion is a trick of human perception that causes the moon to look larger when viewed close to the horizon, especially when framed by terrestrial objects. The Moon’s angular size does not change when it is low in the sky, but the brain interprets its size differently due to these nearby reference points. The best time to observe the Buck Moon is just after sunset when it is rising or just before sunrise as it is setting.
Alternative Names and Cultural Context
While “Buck Moon” is the most widely recognized name in North America, the July full moon carries several other names reflecting different observations and cultural practices. Many Indigenous tribes referred to it as the Thunder Moon due to the frequency of thunderstorms during the hot summer months.
Other names arose from agricultural practices or regional wildlife. Europeans sometimes called it the Hay Moon, signifying the time when the season’s first cutting of hay was traditionally gathered. Some Indigenous groups named it the Salmon Moon, marking the period when the fish returned to the rivers to spawn. These varied names highlight how different cultures used the lunar cycle to anticipate seasonal changes in nature, hunting, and harvesting.