Topline

Although the Blue Moon officially becomes full in the early hours of Sunday, May 31, the key moment is moonrise just after sunset on Saturday, May 30, when it slowly lifts into the eastern sky. That’s when it looks its most dramatic — larger than usual and tinted orange. This is the second full moon in a single calendar month, a simple quirk of timing rather than color, but it creates one of the most visually rewarding naked eye sights in the night sky.

Key Facts

What Is A ‘blue Moon?’

It’s called a Blue Moon because it’s the second full moon in the same calendar month, the first being the full Flower Moon on May 1. The moon takes 29.5 days to orbit Earth and return to the same position in the night sky, causing two full moons in the same month roughly every 2.5 years. The next monthly Blue Moon, like this one, will take place on Dec. 31, 2028.

Why The ‘blue Moon’ Looks Golden

A Blue Moon has nothing to do with color. When a full moon rises, it typically glows orange or deep amber. That’s because its light must travel through a thicker layer of atmosphere near the horizon. Earth’s atmosphere scatters shorter blue wavelengths more efficiently, allowing warmer red and orange tones to dominate — the same effect that produces vivid sunsets.

The times and dates given apply to mid-northern latitudes. For the most accurate location-specific information, consult online planetariums like Stellarium.

Further Reading

ForbesIn Photos: Full ‘Flower Moon’ Lights Up Night Sky Around The WorldForbesWhat Is That Bright Star In The West After Sunset?By Jamie CarterForbesIt’s 100 Days Until A Total Solar Eclipse. Here’s How To See ItBy Jamie Carter