Happy first day of fall, Californians, and never mind the fact that the leaves near you may still be green or the temperatures may be more reflective of summer.

The season began on Monday, Sept. 22, marked by the autumnal equinox.

The autumnal equinox occurs when the center of the sun crosses the celestial equator, or an imaginary line extending Earth’s equator into space, according to NASA and the Old Farmer’s Almanac . An equinox occurs twice a year, the first of which ushers in spring.

Why do we have seasons?

We have seasons because Earth is tilted on its axis as it orbits the sun, said NOAA . For example, the summer solstice in the Northern Hemisphere is when this part of Earth reaches its greatest possible tilt toward the sun, said NOAA. Meanwhile, the Southern Hemisph

See Full Page