Tonight marks the summer solstice, which means Seattleites and the rest of the Northern Hemisphere are saying farewell to spring and ringing in the first day of the summer as well as the longest day of the year.
In Seattle, the moment of the solstice comes at an opportune time: Summer officially begins at 9:24 p.m., just minutes after official sunset at 9:10.
To celebrate the occasion, astronomer and science educator Alice Enevoldsen is hosting a Summer Solstice Sunset Watch at the aptly named Solstice Park in West Seattle.
The family-friendly event kicks off at 9 p.m., even if it’s a cloudy day. People are still welcome to come if it rains, but Enevoldsen says she may stay home with some tea if it rains too hard. Fortunately, the weather is supposed to clear up just before the sun goes down.
Enevoldsen advises sun-watchers to show up early, at around 8:45 p.m., just to make sure they don’t miss the show. “We have noticed that the sun sets about 10 minutes earlier than the USNO [U.S. Naval Observatory] says, because of the horizon altitude,” she writes.
She’ll also give tips for watching August’s solar eclipse from Seattle, as well as from spots in Oregon where the sun will go totally dark.
At the June solstice, the sun is directly over the Tropic of Cancer, providing maximum exposure for the Northern Hemisphere. It’s all part of the variation of seasons, which occurs because of Earth’s tilt with respect to the sun.
The amount of daylight hours during the June solstice depends on where you live. Seattle, for example, sees 15.5 to 16 hours of daylight. Above the Arctic Circle, the sun never sets at this time of year.
Meanwhile, the equator gets 12 hours of daylight and 12 hours of dark, as it does every day. And the Southern Hemisphere is heading from autumn to winter. Antarctica, for example, is experiencing a long stretch of days without ever seeing the sun – which is something Seattleites can sympathize with after last winter’s weather.
GeekWire’s Alan Boyle contributed to this report.