PORTLAND, Ore. (KATU) — Astronomical summer officially begins with the summer solstice on Sunday, June 21, when the sun reaches its northernmost point in the sky for the year.
The June solstice occurs at the moment the sun is directly above the Tropic of Cancer. After that point, the sun begins its apparent journey south again.
In Portland, at about 45 degrees north latitude, June 21 brings nearly 15 hours and 41 minutes of daylight, with sunrise at 5:21 a.m. and sunset at 9:03 p.m.
At noon, the sun reaches its highest point in the sky for the year, about 68 degrees above the southern horizon. The season that begins with the June solstice lasts nearly 93 days, stretching from the solstice to the September equinox.
By comparison, the winter solstice in December brings just under nine hours of daylight in Portland, and the noon sun reaches its lowest point of the year at 21 degrees.
Jim Todd, OMSI’s director of space science education, said the word “solstice” comes from the Latin words sol, meaning sun, and sistere, meaning “to stand still.” On the June solstice, the sun reaches its peak northern position, and its zenith appears to pause before reversing direction and starting to move south again.
The June solstice is also the only day of the year when all locations inside the Arctic Circle experience 24 hours of continuous daylight. Because of atmospheric refraction, the midnight sun can be visible a few days before and after the solstice from areas as far as 60 miles south of the Arctic Circle, Todd said. The farther north someone travels, the more days of the midnight sun they will experience.