Autumnal Equinox 2017: 5 Fast Facts You Need to Know

Today is the fall equinox, aka the autumnal equinox. It is the first official day of autumn where daytime and nighttime are approximately the same lengths. There are two equinoxes every year – in September and March – when the sun shines directly on the equator and the length of day and night is nearly the same. The one in March is known as the spring, or vernal, equinox, and marks the beginning of spring.

Today on the East Coast, the autumnal equinox is at 4:02 pm EDT. In Central Time it is 3:02 PM, in Mountain Time it is 2:02 PM and Pacific Time it is 1:02 PM.

However, today is only the first day of the astronomical fall. The meteorological fall started on September 1. According to the Metro, meteorological seasons are based on the annual temperature cycle and are split into four seasons of three months. With the meteorological calendar, fall lasts until November 30, but the winter solstice isn’t until Thursday, December 21.