The autumn equinox, which will mark the end of summer and the official start of fall in the Northern Hemisphere, will occur in the United States on Monday, September 22, 2025.
The autumn equinox is an astronomical event in which day and night are nearly equal in length; it is a moment of transition that ushers in cooler weather, landscapes of warm colors, and a series of cultural festivities and traditions.
The exact time of the autumn equinox will vary by time zone:
- Eastern Time (EDT): 2:19 PM
- Central Time (CDT): 1:19 PM
- Mountain Time (MDT): 12:19 PM
- Pacific Time (PDT): 11:19 AM
What Is the Autumn Equinox?
The term “equinox” comes from the Latin aequinoctium, meaning “equal night.” Astronomically, it is the moment when the Sun crosses the celestial equator—the projection of Earth’s equator into space. During the autumn equinox, the Sun moves from the Northern Hemisphere to the Southern Hemisphere.
This phenomenon causes sunlight to be distributed almost evenly across both hemispheres, resulting in day and night lasting approximately 12 hours worldwide.
From this date forward, days in the Northern Hemisphere will begin to shorten and nights will lengthen, a trend that will continue until the winter solstice in December.
Fall Traditions and Celebrations in the United States
While the autumn equinox is not a national holiday in the United States with official, universal celebrations, it does mark the beginning of a season rich in traditions and cultural activities. For many, the equinox is a time to connect with nature and celebrate the harvest.
Popular activities and festivities that characterize the fall season in the United States include:
- Apple and pumpkin picking: Many families visit farms to pick their own apples and pumpkins, take hayrides, and enjoy apple cider and other seasonal treats.
- Fall foliage viewing: In many parts of the country, especially in New England and the Appalachians, people travel to admire the spectacular color change of tree leaves, a phenomenon known as “leaf peeping.”
- Harvest festivals: Numerous communities organize festivals to celebrate the local harvest with music, food, and crafts.
- Halloween: Celebrated on October 31, Halloween features costumes, home decorations, the traditional “trick-or-treat,” and themed parties.
- Thanksgiving: Observed on the fourth Thursday of November, it is one of the country’s most important holidays, when families gather to share a hearty meal and express gratitude.
- Spiritual and wellness practices: For some, the equinox is a time for reflection, balance, and gratitude. Practices such as meditation, home cleansing to renew energy, and preparation for the quieter months of winter are common.
