Months without a Full Moon

The moon has mystified people for ages. Many cultures have stories about the man that in the moon and stories that explain the phases of the moon. It is still debatable about whether the moon actually impacts our feelings and emotions, but if you walk into a high school classroom during a full moon, I think you’ll have an answer. Even with our advanced technology, many questions still exist about the moon, but some things are for sure. And one thing that is definitely true about the moon is that the entire month of February can go by without a full moon.

There are usually twelve full moons in a year, and they usually appear once a month. This is because of the waxing and waning of the moon, which is when the moon changes shapes. On average, there is a lapse of 29.53 days (or 29 days, 12 hours, and 44 minutes) between a new moon and the next new moon. This means that it takes about 29 days for the moon to complete it’s cycle and return to its starting phase. So months that have less than 29 days, which is only February, can technically be during the in between phases and not see a full moon. Although this phenomenon is rare, it does occur every few decades, and here’s how.

Say January 31 is a full moon. Then roughly 29 days later, the next full moon arrives. If it is not a leap year, the next full moon would be on March 2. If is a leap year, the next full moon would be on March 1. February is most likely to not have a moon during non-leap years because it has one less day, but it is possible for all Februaries to have no full moon. However, February is the only month, because all the other months are at least 30 days long, which is longer than the average moon’s cycle.

The reason that no moon in February is hard to predict is because the cycle of the moon can change. The way that it revolves around the Earth is not completely circular, and neither is the way that the Earth revolves around the sun. Because of this, sometimes there is a shorter or longer span of time between two full moons. Like I said earlier, 29 days is the average time.

So when can you expect not to see a full moon in February next? 2018 should be the next time that the entire month of February goes by without a full moon. Previously, Februaries of 1809, 1847, 1866, 1885, 1915, 1934, 1961, and 1999 have all skipped the full moon. And with not having a moon in February, these years are the same years that there were two blue moons. This is not a coincidence. In order for February to not have a full moon, one must appear at the very end of January and the very beginning of March. Because of the average 29 day cycle, the 31-day months of January and March will have two full moons. January will also have a full moon at the very beginning and March will also have one at the very end. If the moon deviates from its average cycle length, another month later in the year will play catch-up and have two full moons. Hence, there will be two blue moons within the same year that February does not have one.