Worm Moon: March's Full Moon Explained

The Worm Moon is the full moon traditionally associated with March. In 2027, it reaches its full phase on March 22, less than two days after the March equinox.

Its name is usually connected with the first small creatures stirring as winter loosens its grip. The familiar earthworm explanation is only part of the story, though: an early written account appears to describe insect larvae emerging from beneath tree bark.

When is the Worm Moon?

The Worm Moon is March’s full moon. In 2027, the Moon will reach its full phase on March 22 at 6:44 a.m. EDT, or 3:44 a.m. PDT. Check the fact sheet above for the exact time in your location.

The Moon will be visible through the night of March 21 into the morning of March 22. In eastern North America, the exact phase arrives close to moonset; farther west, it occurs while the Moon is still higher in the sky.

Worm Moon dates by year

Why is it called the Worm Moon?

The popular explanation is that earthworms return to the upper layers of thawing soil in early spring, becoming visible again and providing food for birds. That works as a general image of the season, but it may not be the source of the name.

In a travel account published in 1778, Jonathan Carver described “worms” leaving winter shelters in the bark of trees and other wood. He was probably referring to beetle larvae or similar insects, not earthworms. Carver didn’t identify the community from which he recorded the term, so the passage is really only useful for tracing the English name’s history.

March seasonal names also reflect very different signs of spring. The Great Lakes Indian Fish and Wildlife Commission records *onaabani-giizis*, or Hard Crust on the Snow Moon, in an Ojibwe seasonal calendar. The Citizen Potawatomi Nation uses *Nmebne Gises*, or Sucker Fish Moon, connecting the period with thawing waters and the return of an important food source.

The 2027 Worm Moon, the equinox, and Easter

The March equinox occurs on March 20 at 4:25 p.m. EDT, or 1:25 p.m. PDT, about 38 hours before the Worm Moon. This makes it the first full moon of astronomical spring in the Northern Hemisphere.

The timing also places the Worm Moon close to the calendar rule used for Easter. Western churches celebrate Easter on the Sunday following the ecclesiastical full moon that falls on or after March 21. This ecclesiastical calculation follows a table rather than the directly observed Moon, although the two dates align in 2027: both the ecclesiastical and astronomical full moons fall on March 22, followed by Easter Sunday on March 28.