Love those long, stretched-out summer twilights? You’re in luck: Even though the summer solstice has passed, Seattle is experiencing its longest evening light this week. At 47.6062 degrees north latitude, we experience our latest sunsets of the year after the June 21 summer solstice, not on it.
For several weeks at the beginning of summer, the day is nearly 15 seconds longer than 24 hours, according to Bruce McClure, lead writer for the astronomical website EarthSky.
Therefore, the midday sun, or solar noon, occurs slightly later in the day right now at 1:12 p.m., by clock time, than it does on the June 21 solstice, when solar noon occurred at 1:11 p.m.
“The year’s latest sunset always comes after the summer solstice, even though the exact date of the latest sunset depends on your latitude,” McClure wrote. “Farther north — at Seattle — the latest sunset happened around June 25. Farther south — at Mexico City or Hawaii — the latest sunset won’t happen until early July.”
McClure explained that if the Earth’s axis stood straight upright and the same distance from the sun throughout its orbit, clock time and sun time would always agree.
“However, the Earth’s axis is titled 23.44 degrees out of vertical, and our distance from the sun varies by about 3 million miles throughout the year. At and around the equinoxes, solar days are shorter than 24 hours, yet at the solstices, solar days are longer than 24 hours,” he wrote.
So, it’s not really a longer day, he said; just a discrepancy between the sun and the clock. But still, if you love summer sunsets, you might as well enjoy them now.
In the morning in Seattle on June 27, astronomical twilight, which is when the sun is 18 degrees below the horizon, began at 2:07 a.m. Nautical twilight, when the sun was 12 degrees below the horizon, began at 3:36 a.m. Civil twilight, also known as dawn, began at 4:33 a.m. The sun rose at 5:13 a.m.
Sunset occurs at 9:11 p.m., with civil twilight, also known as dusk, ending at 9:51 p.m.