SUMMER OFFICIALLY ARRIVES on the North Olympic Peninsula at 10:16 a.m. today, the instant the Northern Hemisphere reaches the summer solstice.
Though the summer solstice lasts only an instant, the term is often used to refer to the full day and night on the day of the event — the so-called longest day of the year because of the maximum daylight.
The solstice occurs when the sun’s position in the sky is at its greatest angular distance from the equatorial plane; in other words, Old Sol will appear in the ksy to be at its northernmost point of the year today.
Conversely, today marks the winter solstice south of the equator. People there will experience their shortest daylight period of the year.
The National Weather Service in Albuquerque, N.M., explains summer solstice and other seasonal phenomenon here: http://tinyurl.com/5w8tvy4