First Day of Fall in North America: Autumn Equinox

Date

Typically September 22 or 23 (varies by year and time zone).

Astronomical Definition

Moment the Sun crosses the celestial equator moving southward. Day and night ~equal length globally.

2024–2026 Dates (EDT)

• 2024: Sept 22, 8:44 AM
• 2025: Sept 22, 2:20 PM
• 2026: Sept 23, 8:05 AM

Meteorological Fall

For climate records: September 1 (fixed 3-month seasons).