autumnal equinoxes
Fall's equal days
Autumnal equinoxes is the plural of autumnal equinox—the moment in September when the sun crosses the celestial equator moving southward, making day and night roughly equal in length.
It marks the beginning of autumn in the Northern Hemisphere: The autumnal equinoxes of 2020 and 2021 fell on September 22.
- astronomical eventNotable occurrence in space
- astronomicalRelating to outer space
- crispnessSnappy, firm texture
- sweater weatherMild cold requiring knitwear
- fall foliageSeasonal leaf coloration
falling leaves · harvest · harvest festival · axial tilt · equinoxes · frosts · pumpkin spice · apple picking · calendar · perihelion · migratory patterns · falls · pagan traditions · changing seasons · balances · horizons · harvest moon · celestial navigation
autumnal equinoxessolstices
Annual solar standstill events
solstice · summer solstices · winter solstices · June solstice · December solstice
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