August 2025 Sturgeon Moon: A Rare Month with Two First Quarter Moons in Every Time Zone

August 2025 brings the Sturgeon Moon, named after North America's giant freshwater fish, along with a rare lunar alignment—two First Quarter Moons occurring in every time zone on Earth. Here's your complete guide to August's moon phases, close planetary approaches, and the science behind this unusual calendar quirk.

August 2025: The Sturgeon Moon and a Rare Lunar Double Feature
When to See the August Full Moon
The Full Moon of August—known as the Sturgeon Moon—will shine at its brightest at 07:54 UTC on August 9, 2025. For several nights before and after, the Moon will appear full, casting its silvery glow across the night sky. During this phase, the Moon rises near sunset and sets around sunrise, staying visible all night long. Two weeks later, on August 23, the New Moon marks another astronomical milestone—a Black Moon, the third New Moon in a single astronomical season that contains four.

Why It’s Called the Sturgeon Moon
The Sturgeon Moon’s name comes from the abundance of sturgeon fish historically caught in the Great Lakes and major rivers of North America during August. Other traditional names for this moon include Grain Moon, Corn Moon, Lynx Moon, and Lightning Moon, reflecting seasonal changes and natural events in different cultures.

August 2025 Moon Phase Calendar
Moon phases occur at the same moment worldwide, but the local time depends on your time zone. This is why lunar calendars are linked to specific locations—what’s August 1 in one place could still be July 31 elsewhere. In August 2025, moonwatchers everywhere will witness a rare event—two First Quarter Moons in a single month no matter where they live.

A Rare Double First Quarter Moon in Every Time Zone
The first First Quarter Moon will occur at 12:41 UTC on August 1. For Baker Island and Howland Island (UTC-12), this happens at 00:41 local time—just 41 minutes after August begins.

The second First Quarter Moon takes place at 06:25 UTC on August 31. For Kiritimati (UTC+14), this is at 20:25 local time—only 3½ hours before the month ends. This is an incredibly tight scheduling fit—there’s almost no margin for error on either end of the month.

Why It’s So Rare
The Moon’s average cycle from one phase to the next is 29.54 days, but in this case, the cycle between the two First Quarters is 29.74 days—nearly five hours longer than usual. The last time a similar event occurred across all time zones was in August 2023, with two Full Moons. However, that cycle was shorter—29.29 days—so the fit was less precise.

The Moon’s Close Encounters in August August 2025 will also bring several notable celestial pairings: August 12–13 – The Moon passes near Saturn. August 16 – A close approach to the Pleiades star cluster. While July’s approach included a lunar occultation visible from North America, this month’s occultation will be visible from parts of East Asia. August 20 – The Moon, Jupiter, and Venus form a spectacular trio in the evening sky. August 26 – A close approach to Mars, best viewed from New York and Sydney (London’s evening sky will still be too bright).
Cultural and Seasonal Significance
Moon names like Sturgeon Moon, Harvest Moon, and Flower Moon were once essential for marking agricultural cycles, hunting periods, and seasonal changes. Today, they serve as reminders of the deep human connection to the rhythms of the sky.