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EmailSee chart below to see the exact dates and times for the first day of each season in 2013—namely, the summer solstice, fall or autumnal equinox, winter solstice, and spring or vernal equinox.
Why do the seasons change? The four seasons are determined by shifting sunlight (not heat!)—which is determined by how our planet orbits the Sun and the tilt of its axis.
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The first day of summer—the summer solstice—is the longest day of the year, the Sun reaches its most northern point in the sky at local noon. After this date, the days start getting shorter. See our First Day of Summer page!
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On the first day of fall—the autumnal equinox—day and night are each about 12 hours long (with the actual time of equal day and night, in the Northern Hemisphere, occurring a few days after the autumnal equinox). The Sun crosses the celestial equator going southward; it rises exactly due east and sets exactly due west. See our First Day of Fall page!
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The start of winter—the winter solstice—is the shortest day of the year, when the Sun reaches its most southern point in the sky at local noon. After this date, the days start getting longer. See our First Day of Winter page!
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On the first day of spring—the vernal equinox—day and night are each approximately 12 hours long (with the actual time of equal day and night, in the Northern Hemisphere, occurring a few days before the vernal equinox). The Sun crosses the celestial equator going northward; it rises exactly due east and sets exactly due west. See our First Day of Spring page!
Credit: NASASeasons of 2013: SPRING EQUINOX March 20, 7:02 A.M. EDT SUMMER SOLSTICE June 21, 1:04 A.M. EDT FALL EQUINOX September 22, 4:44 P.M. EDT WINTER SOLSTICE December 21, 12:11 P.M. EST Seasons of 2014: SPRING EQUINOX March 20, 12:57 P.M. EDT SUMMER SOLSTICE June 21, 6:51 A.M. EDT FALL EQUINOX September 22, 10:29 P.M. EDT WINTER SOLSTICE December 21, 6:03 P.M. EST -
Comments
Great question. You are
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By Almanac Staff
Great question. You are correct. The "equal" night/day usually comes a few days before the equinox. Our former astronomer, George Greenstein, had this to say: "There are two reasons. First, light rays from the Sun are bent by the Earth's atmosphere. (This is why the Sun appears squashed when it sets.) They are bent in such a way that we are actually able to see the Sun before it rises and after it sets. The second reason is that daytime begins the moment any part of the Sun is over the horizon, and it is not over until the last part of the Sun has set. If the Sun were to shrink to a starlike point and we lived in a world without air, the spring and fall equinoxes would truly have ‘equal nights.’”
I have a fairly simple
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By yug
I have a fairly simple question.
Does the winter solstice in the Northern hemisphere occur at the same time as the summer solstice in the Southern hemisphere?
If there is a lag in the exact time, is that lag due to the "wobble" of the Earth on it's axis?
Enquiring minds wander...
yug...
Yes, both solstices occur at
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By Miranda Mowrey
Yes, both solstices occur at the same time. The northern axis points towards the Earth, creating more exposure, summer. On the directly oppisite side of the world, the southern hemisphere is in winter, because the southern axis is pointed away from the sun, becoming less exposed to sunlight. Both are solstises because the sun is either facing the Northern or Southern hemisphere, not the equator, which results in equinox. :)
Hi All, It is my
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By Heidi Stonehill
Hi All,
It is my understanding that the winter solstice in the Northern Hemisphere and the summer solstice in the Southern Hemisphere occur at the same point in time. However, local time, due to time zones, will vary. At the December solstice, Earth reaches a spot in its orbit such that its northern axis points the farthest away from the Sun (Earth's axis is tilted 23.5 degrees away from an upright position). The timing of this event is not dependent on where you are on Earth (such as a sunrise would be). However, the local time will change. Astronomers often list these events in Universal Time (UT), which is tied in to the time at Greenwich, England (0 degree longitude). From there, we need to convert to our local time.
Sometimes, the seasons occur near midnight. Therefore, as the event gets translated into local time, it may occur on one of two days (late evening of one day or early morning of the next day). This situation is happening for the December solstice in 2011. In Universal Time, the December solstice occurs on December 22 at the 5th hour 30th minute. In Eastern Standard Time, this is 12:30 am on December 22. However, in Central Time, this is December 21 at 11:30 pm; Mountain Standard is December 21 at 10:30 pm; Pacific Standard is December 21 at 9:30 pm, etc.
Hope this helps!
Heidi Stonehill
The Old Farmer's Almanac
Thanks Heidi!
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By Anonymous Al
Thanks Heidi!
After reading this I, of
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By Harry Cohoon
After reading this I, of course understand the time zones, but it seems the season change may be at the same time all over the US? or does it come one hour after the previous time zone? In example Spring at 0700 EDT is also at 0700 CST?
A good question. Perhaps some
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By neilyogi
A good question. Perhaps some Australians can help
It would appear that the
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By neilyogi
It would appear that the Solstice occurs this year on both the 21st and the 22nd -- depending on your time zone -- am I wrong?
Happy Autumnal Equinox 2011.
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By shand
Happy Autumnal Equinox 2011. After Spring, Fall is my fave time of year. Love the smell of the fresh air as the temps change.
Love the Almanac ,too. From the time I was about 13 my Mom always made sure Santa put a copy of the Almanac in my Xmas stocking. Always something interesting to learn. Since my parents have moved on to the 'next realm' I make sure to get myself an Almanac for Xmas every year. It gets picked up by everyone that stops by over the holidays.
I always look at the almanac
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By marycorns
I always look at the almanac to help me figure out when I'm going to plant my vegetable garden each year. It is something that my grandmother taught me to do to get the most out of the gardening season. I've even planted my vegetables in pots before the season starts so that I can transplant them outside and get a head start.
The Almanac sits near our
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By ColoRay
The Almanac sits near our couch and is viewed often and by many... Thanks So Much
I love the Almanac, too. It
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By Kimberley
I love the Almanac, too. It is full of interesting and very important information. Thanks, Kimberley
There is so much to learn
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By Reade Linam
There is so much to learn from studying the past. Washington is no match for Mother Nature.
I love the Almanac
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By drewjpeterson
I love the Almanac
What would we do without
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By Dwight Doggett
What would we do without it?
I for one would be lost
when does the northern
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By kylee
when does the northern hemisphere have spring? Some years it will be on a different day or years.;
My Mother used to get these
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By Deremiah CPE
My Mother used to get these same exact Almanac's back in the day...it's sooo beautiful making this connection. KEEP READING this stuff...I love you...by Deremiah *CPE
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