On November 5, 2025, skywatchers will witness the rise of the biggest full moon of the year, often referred to as a supermoon. This celestial event will illuminate the night sky at precisely 5:30 p.m. EST (or 2230 GMT) when the moon reaches its closest point to Earth, known as perigee, at a distance of 221,726 miles (or 356,833 kilometers). Remarkably, the full moon will officially occur nine hours and eleven minutes before this moment, showcasing the moon's grandeur.
While a full moon is often thought to last only a moment, this moment is imperceptible to the naked eye. For a day or so surrounding the full moon, many observers will describe the moon as “full,” even when it is technically a waning gibbous moon. The narrow shaded strip that indicates the moon is not completely full changes so slowly that it is difficult to notice without close observation.
Many media outlets hype the supermoon as a unique astronomical event, prompting people to rush outdoors in anticipation. This excitement can be compared to the whimsical tale, “The Emperor's New Clothes,” by Hans Christian Andersen. Although the November full moon will indeed be the biggest of 2025, the difference in size might not be readily apparent to most observers. The moon reaches perigee once or twice a month, with varying distances, but this particular occurrence will be the closest full moon of the year.
Next year, on May 31, 2026, a full moon will coincide with apogee, which is its farthest point from Earth. This apogee full moon will appear about 14% smaller and is often referred to as a micro-moon. Additionally, the common notion that the supermoon is 30% brighter than usual is a misconception; the brightness difference only amounts to about 0.2 to 0.3 magnitudes, which is hardly noticeable to the human eye.
The near coincidence of this full moon with perigee will result in significantly larger ocean tides, known as perigean spring tides. These tides can exacerbate coastal flooding during storms or create unusually low tides if strong winds push water offshore. Spring tides occur when the moon is at full or new phases, aligning with the sun to amplify tidal effects.
This month's full moon is approximately 12.2% closer at perigee compared to the apogee full moon in May, resulting in a 46% increase in tidal force. However, the highest tides will not coincide with the perigee moon; they will typically lag by one to two days, depending on the coastal location. For instance, in Cape Fear, North Carolina, the highest tide will reach 6.88 feet at 7:20 a.m. EST on November 6, while in New York City, the peak will be 6.34 feet at 7:59 a.m. EST.
Despite the excitement surrounding the supermoon label, it is important to note that the moon reaches perigee monthly. Consequently, some full moons that flank perigee are also branded as supermoons. For example, the full moon on October 6, 2025 was labeled a supermoon, as will the one on December 4, 2025.
Interestingly, many supermoons can occur in a year, with some years featuring as many as five. The question arises: why are supermoons only celebrated during full moons? On February 24, 2026, a first quarter moon will be less than eleven hours from perigee, but this event does not generate the same excitement.
As renowned astrophysicist Dr. Neil deGrasse Tyson aptly put it, the relatively small increase in the moon's apparent size may not be as significant as the hype suggests. To illustrate, transforming a 14-inch pizza into a 15-inch pizza doesn't exactly make it a “super-pizza.” In the grand scheme of our natural satellite, it seems that size may not matter after all.
