CHEYENNE, Wyo. (KGWN) - The Autumnal Equinox took place at 7:54 p.m. Saturday.
Equinox means equal hours of day and night. This happens because the Earth's axis isn't tilted at all. The Autumnal Equinox signifies the transition from summer to winter because following the equinox the Earth will start to tilt the Northern Hemisphere away from the sun.
Each year the Autumnal Equinox falls on a different day between September 20 and September 24 because while the calendar year is 365 days, it actually takes the Earth 365.25 days to rotate all the way around the sun.
As the transition to cooler temperatures continues, be sure to be weather aware and prepared for all kinds of winter weather.