Autumn Equinox 2025 Uk. But how will it affect the uk? Usually, when we talk about the first day of autumn we are referring to the astronomical autumn which is defined by the earth's axis and orbit around the sun.

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. They occur between the summer and winter.