PORTLAND, Ore. (KOIN) — Summer officially begins at 8:32 p.m. Sunday. In case you’ve forgotten what the summer solstice is, OMSI’s Jim Todd provided this information for a refresher course.
When the solstice happens, Earth’s north pole is at its closest point to the sun at its maximum of 23° 26′. Technically it only lasts an instant, but more commonly refers to the day it happens. This is also the longest day of the year — that is, it’s the day with the longest period of sunlight. (Yes, this means the days begin to get shorter again until it’s late December and it gets dark at 4 p.m.)
So on the summer solstice, Earth is tilted so that the north pole is at its closest point with the sun.
But in 2 weeks, on July 5, Earth itself will be at its farthest distance from the sun. That’s called aphelion (the opposite of perihelion, when Earth’s orbit is nearest to the sun.)
Remember, there are 2 summer solstices each year. In June it’s in the Northern Hemisphere and then in December (when it’s dark and cold here) it’s summer in the Southern Hemisphere.
Got all this? There’s a pop quiz on Friday. Don’t forget your sunscreen.