Overview
- The equinox occurred at 14:46 UTC on March 20, the precise instant the Sun crossed the celestial equator and the seasons changed.
- Mexico’s official timing was 08:46 a.m. Central Time, per the INAOE, though some outlets reported small minute-level differences.
- Argentina’s Servicio de Hidrografía Naval set the autumnal equinox at 11:46 a.m. Hora Oficial Argentina, confirming the season’s start on Friday.
- Mexico’s Secretaría de Cultura and INAH ran an Equinox Operation from March 20–22 at archaeological zones, enforcing entry rules and adjusted schedules at sites including Teotihuacán and Chichén Itzá.
- Experts explained that day and night are not exactly 12 hours at the equinox because the Sun is a disk and the atmosphere refracts its light, and coverage linked the new season to weather outlooks and heat-health advice.