The astronomical start to the summer season began Tuesday morning, despite recent temperatures going above normal in San Diego County.
The official start of the summer begins at the solstice on June 21, resulting in the longest period of daylight and shortest night of the calendar year. The transition occurs when the earth's North Pole is at a maximum tilt of about 23.5 degrees toward the sun, according to the National Weather Service.
The sunrise in San Diego was at 5:41 a.m, and the sun will set at 8:00 p.m., resulting in a total day length of 14 hours and 19 minutes.
The summer solstice occurs when the sun is directly over the Tropic of Cancer. The sun is at its highest point in the sky for every place north of the Tropic of Cancer.
Solstices happen every June and December, occurring at the same time around the world and marking the year's longest and shortest days.
According to the National Weather Service, the Northern Hemisphere receives sunlight at the most direct angle of the year during the summer solstice. Unlike astronomical seasons, based on the position of Earth in relation to the sun, meteorological seasons are based on the annual temperature cycle.
According to National Centers for Environmental Informaiton, meteorologists and climatologists break the seasons down into groupings of three months based on the annual temperature cycle and calendar. Associating winter being the coldest time of the year, the summer as the warmest, and the transitional seasons of spring and fall are the basis of meteorological seasons.
Astronomical seasons follow the earth's natural rotation around the sun, bringing two annual solstice and equinoxes
Equinoxes occur near March 21st and near September 22nd, when the earth’s axis is tilted neither toward nor away from the sun, resulting in an equal amount of daylight and darkness at all latitudes. Seasons are caused by the earth's tilt of 23.5 degrees. In the Northern Hemisphere, the summer solstice falls on or around June 21, and the winter solstice on or around December 22. These seasons are reversed but begin on the same dates in the Southern Hemisphere.
