A Blue Moon, defined as the second full moon in a single calendar month, typically occurs about every 2 to 3 years on average. This means roughly every 2.4 to 2.5 years, with about 41 Blue Moons occurring each century. The timing can vary slightly depending on time zones, but it remains a relatively infrequent event astronomically. Despite the name, a Blue Moon does not literally appear blue—it just signifies having two full moons in one month. Months with 31 days are more likely to host a Blue Moon, while February can never have one due to its shorter length. There can also be rarer events such as two Blue Moons occurring in a single year, which happen about four times per century.