2012 Fall Equinox Arrives Saturday Morning

Friday was the last day of summer 2012, and fall is just hours away — that means another fall (or autumnal) equinox is coming. In the Pacific region, it arrives at 7:49 a.m. Saturday.

But what is the autumnal equinox? 

Equinoxes fall on the halfway point between solstices and occur, according to the Washington Post, "when the sun crosses the equator and day and night are of roughly equal length, everywhere in the world."

The nearly equal 12 hours of light and darkness can be attributed to the Earth's lack of an axial tilt on the day of the equinox. In fact, the word equinox is derived from the Latin words aequus, meaning equal, and nox, meaning night.

In Napa, according to sunrisesunset.com, the sun will come up at 6:58 a.m. and set at 7:05 p.m on the autumnal equinox.

As you notice, that is not actually a perfect 12 hours of light and darkness. As timeanddate.com reports, this is because of issues such as light refraction and other reasons.

And while Saturday ushers in autumn, our weather in the Napa Valley is expected to be sultry once the morning fog burns off: Expect temperatures in the low to mid-80s.

Napa Patch becomes Napa Valley Patch Sept. 27: Follow us on Twitter | Like us on Facebook | Sign up for the daily email with links to the latest news | Got something to say? Start a blog and share your views with the valley.