The weather might not feel like it, but the calendar says Wednesday, March 20, is the official first day of spring (or the vernal equinox for you astronomy majors) in the Northern Hemisphere.

So what do you need to know about March's equinox? Check out these facts, courtesy of About.com and Wikipedia:

• The strict definition of the spring equinox is when the center of the sun is directly over the Equator. On Wednesday, March 20, 2013, that was at 11:02 UT (Universal Time or Greenwich Mean Time). Or 4:02 a.m. local time.
• Although the spring equinox is said to have equal hours of day and night, that's usually not the case. That spring day most likely happens before the equinox on the calendar.
• Then there's the balancing egg treat. According to legend—or uncontravertible scientific fact—an egg will balance on its end only during the vernal equinox. There's not a lick of truth to it. Nada. Nil. In fact, it was debunked on an episode of The West Wing (see video), and if you can't trust President Bartlet, who can you trust? (Mythbusters also disproved it in case the word of a fictional U.S. president isn't good enough for you.) Sure, you might be able get an egg to balance on that day, but it has nothing to do with the equinox.

Of course, the most important information to know about the spring equinox is what will Wednesday's weather be like? According to the National Weather Service, the day will be mostly sunny, with blustery wind gusts as high as 30 mph. The high will top out around 26 degrees, with a low of 15.

Yes, it's not the ideal spring day, filled with robins tweeting, gentle breezes and mild temperatures. But it's the only first day of spring day we have in 2013, so let's document it. Share your photos of Wednesday by uploading them to this story or to Patch's Neighborhood Gallery. Some of them might even be used as cover photos on our Facebook page.

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