when is the next blue moon

The next Blue Moon will occur on May 31, 2026. It will be a calendrical Blue Moon, meaning it is the second full moon in a calendar month or a rare occurrence based on the lunar calendar. The next seasonal Blue Moon will happen on May 20, 2027. Blue Moons generally happen about every 2.5 to 3 years, and the moon itself does not actually appear blue in color during these events—it is mostly a calendrical term.