1  Summertime, and the tiltin’ is easy. Summers are hot not because Earth is closer to the sun, but because the tilt of the Earth’s axis lets rays of sunlight hit one hemisphere more directly.

2  During the Northern Hemisphere’s summer, we’re actually farthest from the sun, receiving 7 percent less sunlight than the Southern Hemisphere does during its summer.

3  The summer solstice—June 20 this year—is the Northern Hemisphere’s longest day, with 24 hours of unbroken sunlight north of the Arctic Circle.

4  For obsessive-compulsives: The site www.archaeoastronomy.com maintains a second-by-second countdown to each solstice.

5  Supporters of Seattle’s Solstice Parade, an annual fixture of the city’s artsy Fremont neighborhood, proclaim that it will “cast a spell of joy, hope, and rebirth that spreads from Fremont to the entire universe.”

6  Helping cast the spell are the Painted Cyclists, a clothing-optional group of bike riders who wear intense body makeup.