When is Blue Moon in 2015?

The Blue Moon in 2015 occurs on Friday, July 31st. 

What is Blue Moon?

Traditionally, the term Blue Moon refers to the rare additional full moon that appears in season. Recently, it has come to mean the second full moon that occurs in a single month of the solar calendar. Typically, this full moon event occurs every 2-3 years. People often use the term Blue Moon to describe sometime that rarely occurs. The phrase itself has absolutely nothing to do with the color of the moon.