From the ABC 7 Weather team

Ready or Not, Daylight Getting Shorter Each Day

September 25, 2012 - 04:57 PM
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As temperatures start to drop with the autumn season, the hours of daylight get shorter, too.

If you're anything like me, you're welcoming the cooler and more seasonable autumnal air that has settled in over the region, as of late.  The autumnal equinox occurred on Saturday, September 22nd at 10:49am. Until the winter solstice, the North Pole will continue to tilt farther away from the sun.  What does this mean for us, in the Northern Hemisphere?  Well, shorter daylight and cooler temperatures.  So how much daylight will we lose until the winter solstice on December, 21st?  Starting with today, Tuesday, September 25th, we have just about equal parts of daylight and darkness.  By the end of October, we'll have lost about an hour and a half of daylight and by the winter solstice, we'll only have about 9 and a half hours of daylight.

Duration of Daylight in D.C.

I found a neat image of an analemma that gives a great visual of the placement of the sun from the vernal equinox through the autumnal equinox . What's an analemma?  It's a sequence of the sun at the same time of the day at different days of the year.  It looks like a figure eight curve.

Tunç Tezel (TWAN)

This particular image was taken at the same time on 17 different days from April 2nd through September 16, 2012. The highest sun was on June 20, the summer solstice, at the northernmost declination. The two closest to the horizon are near the equinoxes.  You can clearly see the sun's position at different times of the year and how high/low in the sky the sun is in relation to the season. 

If you're not a big fan of the shorter daylight hours, we'll start gaining daylight after December 21st.

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