First Day Of Autumn 2025 Canada 2025. Meanwhile, meteorological fall begins on sept. Autumn equinox 2025 (beginning of astronomical autumn) on the day of the autumn (september) equinox, the sun, moving along the ecliptic, crosses the celestial equator, moving from the.

 — first day of fall 2025. The earth’s fixed tilt as it orbits the sun leads to this day.