Published: June 20,2014
For much of the country, temperatures have already reached well into
the 80s since at least early May. Meteorologically speaking, summer has
already started since atmospheric researchers consider June 1 as the
first day of the summer season.
But astronomically, the summer solstice, more commonly known as the first day of summer, will arrive Saturday, June 21, 2014 at 6:51 a.m. EDT.
The Science Behind the Summer Solstice
The change of seasons can be attributed to the tilt of the earth's axis and the earth's revolution around the sun.
Recall that the earth spins on a tilted axis, and that the angle of the tilt is 23.5 degrees from the earth's geographical poles. This tilt allows for direct sunlight to be aimed at various latitudes of the earth with every revolution around the sun (one revolution is approximately 365.25 days).
During the summer, the northern hemisphere receives the most direct sunlight because the northern hemisphere is tilted toward the sun. On June 21, the sun's rays will be located directly overhead at the Tropic of Cancer, a line of latitude located at 23.5 degrees north of the equator.
For areas farther north of the Tropic of Cancer, the sun will be at
its highest point in the sky at noon on June 21, and those locations
will experience their longest amount of daylight in one day the year.
For example, in Dublin, Ireland (latitude of 53.3 degrees), the sun will rise at 4:57 a.m. local time on June 21 and will not set until 9:57 p.m. local time. That's 17 hours of sunlight.
Meanwhile, in Dallas, Texas (latitude of 32.8 degrees), the sun will rise at 6:20 a.m. local time and will set at 8:38 p.m. local time — a total of 14 hours and 18 minutes.
Soon after the summer solstice, the length of daylight in the northern hemisphere will gradually grow shorter each day until the winter solstice in December, when the shortest amount of daylight occurs.
(MORE: 10 Ways to Enjoy the Longest Day of the Year)
Forecast for the First Day of Summer
Looking to host a Summer Solstice pool party, or to catch a movie under the stars on Saturday? Bring an umbrella or have some indoor back up plans, especially if you live in parts of the Southeast and Midwest.
Scattered showers and thunderstorms are expected from Virginia south into Florida. In addition, a separate area of low pressure located in central Canada will swing a cold front into the northern Plains, firing off storms that will bring yet more heavy rain to this already saturated area. Other clusters of thunderstorms are possible in parts of the Tennessee Valley, Mississippi Valley, Rockies and Rio Grande Valley.
(MORE: Dangerous Flooding in South Dakota, Minnesota and Iowa)
Otherwise, hot temperatures will continue for the Southwest, where high temperatures rise over the triple digit mark. Temperatures will swell into the 90s for much of the Deep South and central Plains, while thermometers will hover in the 70s to 80s for the rest of the country.
MORE: Summer Solstice Around the World
But astronomically, the summer solstice, more commonly known as the first day of summer, will arrive Saturday, June 21, 2014 at 6:51 a.m. EDT.
Why the Seasons?
(NOAA/NWS)The change of seasons can be attributed to the tilt of the earth's axis and the earth's revolution around the sun.
Recall that the earth spins on a tilted axis, and that the angle of the tilt is 23.5 degrees from the earth's geographical poles. This tilt allows for direct sunlight to be aimed at various latitudes of the earth with every revolution around the sun (one revolution is approximately 365.25 days).
During the summer, the northern hemisphere receives the most direct sunlight because the northern hemisphere is tilted toward the sun. On June 21, the sun's rays will be located directly overhead at the Tropic of Cancer, a line of latitude located at 23.5 degrees north of the equator.
Summer Solstice
For example, in Dublin, Ireland (latitude of 53.3 degrees), the sun will rise at 4:57 a.m. local time on June 21 and will not set until 9:57 p.m. local time. That's 17 hours of sunlight.
Meanwhile, in Dallas, Texas (latitude of 32.8 degrees), the sun will rise at 6:20 a.m. local time and will set at 8:38 p.m. local time — a total of 14 hours and 18 minutes.
Soon after the summer solstice, the length of daylight in the northern hemisphere will gradually grow shorter each day until the winter solstice in December, when the shortest amount of daylight occurs.
(MORE: 10 Ways to Enjoy the Longest Day of the Year)
First Day of Summer
Looking to host a Summer Solstice pool party, or to catch a movie under the stars on Saturday? Bring an umbrella or have some indoor back up plans, especially if you live in parts of the Southeast and Midwest.
Scattered showers and thunderstorms are expected from Virginia south into Florida. In addition, a separate area of low pressure located in central Canada will swing a cold front into the northern Plains, firing off storms that will bring yet more heavy rain to this already saturated area. Other clusters of thunderstorms are possible in parts of the Tennessee Valley, Mississippi Valley, Rockies and Rio Grande Valley.
(MORE: Dangerous Flooding in South Dakota, Minnesota and Iowa)
Otherwise, hot temperatures will continue for the Southwest, where high temperatures rise over the triple digit mark. Temperatures will swell into the 90s for much of the Deep South and central Plains, while thermometers will hover in the 70s to 80s for the rest of the country.
MORE: Summer Solstice Around the World
Summer Solstice Around the World
Getty Images
A visitor scans the skyline and harbour of
Sydney from a viewing platform at the Sydney Tower Eye in Sydney,
Australia. (Eugene Tan/Hausmann Communications via Getty Images)
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