Phases glossary
What is the Harvest Moon?
Harvest Moon is the traditional name for the full Moon nearest the Northern Hemisphere's September equinox.
What it means
Harvest Moon belongs to the Moon's repeating cycle of illumination. Lunar phases are produced by the changing Sun-Earth-Moon geometry, not by Earth's shadow; Earth's shadow is involved only during a lunar eclipse. The same phase is visible worldwide at a given moment, although its orientation can look different by latitude and hemisphere.
For a deeper look with practical observing advice, read the Moonrise Moment guide to harvest moon.
Sources and further reading
This definition was written in plain language and checked against these science references.