Blue Moon visible Sunday across the Americas

A second full moon this month, known as a “Blue Moon,” will be visible on the night of May 31‑June 1. The phenomenon occurs when two full moons fall within a single calendar month, a result of the lunar cycle (≈29.5 days) being shorter than most months. Despite its name, the Moon will retain its usual grey‑white appearance.

The Blue Moon will also coincide with a microluna, meaning the Moon is near its farthest point from Earth, making it about 5.5 % smaller and up to 10.5 % dimmer than a typical full Moon. The difference is subtle and unlikely to be noticeable without instruments. Observers in Ciudad Juárez (Mexico) and the Dominican Republic, along with many regions in the United States, Europe, Asia, Africa, South America, Australia and New Zealand, can view the event, best from dark sites away from city lights. After this occurrence, the next Blue Moon is not expected until December 2028.